[424B2] Citigroup Inc. Prospectus Supplement

Rhea-AI Filing Summary

ServiceTitan, Inc. (symbol: TTAN) has filed a Form 144 announcing the proposed sale of 390 Class A common shares on 07 July 2025 through Merrill Lynch. The filing states an aggregate market value of $42,705 for the new transaction and lists 5,770,464 Class A shares outstanding.

More notably, the form discloses extensive sales executed during the preceding three-month period by investment vehicles affiliated with Bessemer Venture Partners and 15 Angels II LLC. Across 21 separate trades between 10 June 2025 and 03 July 2025, these entities disposed of approximately 931,364 Class A shares for total gross proceeds of about $97.6 million. The largest single-day sale occurred on 10 June 2025, when Bessemer Venture Partners VIII Institutional L.P. sold 266,502 shares for $27.18 million.

Combined, the past-quarter disposals represent roughly 16% of the current shares outstanding, signalling sustained distribution by major early investors. The forthcoming 390-share sale is immaterial in isolation, but the aggregate selling trend may raise supply-side concerns for public shareholders.

No earnings, operational updates, or other corporate developments are included in this filing. The signatory attests to the absence of undisclosed material adverse information, in line with Rule 144 requirements.

Positive

• None.

Negative

• Large insider/VC selling: Approximately 931,364 Class A shares (about 16% of shares outstanding) were sold in the last 3 months for $97.6 million, indicating potential overhang and reduced insider ownership.

Insights

Equity Research Analyst

TL;DR: ~931k insider shares sold (~16% float); small new sale adds to supply pressure.

The Form 144 itself covers only 390 shares, but the attached sales history is the real story: venture funds linked to Bessemer off-loaded roughly 0.93 million shares over three weeks, pulling nearly $98 million from the market. With just 5.77 million Class A shares outstanding, the selling wave is material and may weigh on TTAN’s near-term share price by increasing free float and signalling reduced insider conviction. No balancing positive catalysts or corporate updates are provided, leaving the disclosure tilted negative for sentiment. Impact is assessed as meaningful for investors tracking ownership dynamics and potential market-overhang risk.

The information in this preliminary pricing supplement is not complete and may be changed. A registration statement relating to these securities has been filed with the Securities and Exchange Commission. This preliminary pricing supplement and the accompanying product supplement, underlying supplement, prospectus supplement and prospectus are not an offer to sell these securities, nor are they soliciting an offer to buy these securities, in any state where the offer or sale is not permitted. SUBJECT TO COMPLETION, DATED JULY 8, 2025

Citigroup Global Markets Holdings Inc.

July     , 2025 Medium-Term Senior Notes, Series N Pricing Supplement No. 2025-USNCH27498 Filed Pursuant to Rule 424(b)(2) Registration Statement Nos. 333-270327 and 333-270327-01

Enhanced Geared Buffered Digital Securities Linked to the Worst Performing of the Health Care Select Sector SPDR^® Fund, the Russell 1000^® Growth Index and the Russell 2000^® Index Due July 21, 2026

▪The securities offered by this pricing supplement are unsecured debt securities issued by Citigroup Global Markets Holdings Inc. and guaranteed by Citigroup Inc. Unlike conventional debt securities, the securities do not pay interest and do not repay a fixed amount of principal at maturity. Instead, the securities offer a payment at maturity that may be greater than or less than the stated principal amount, depending on the performance of the worst performing of the underlyings specified below from its initial underlying value to its final underlying value.

▪The securities offer modified exposure to the performance of the worst performing underlying, with (i) a digital (fixed) return at maturity so long as the final underlying value of the worst performing underlying is greater than or equal to its final buffer value and (ii) if the final underlying value of the worst performing underlying is less than its final buffer value, a limited buffer against the depreciation of the worst performing underlying as described below. In exchange for these features, investors in the securities must be willing to forgo (i) any appreciation of the worst performing underlying in excess of the digital return and (ii) any dividends with respect to any underlying. In addition, investors in the securities must be willing to accept downside exposure to any depreciation of the worst performing underlying in excess of the buffer percentage specified below. If the worst performing underlying depreciates by more than the buffer percentage from its initial underlying value to its final underlying value, you will lose more than 1% of the stated principal amount of your securities for every 1% by which that depreciation exceeds the buffer percentage. Accordingly, the lower the final underlying value, the less benefit you will receive from the buffer percentage. You may lose your entire investment in the securities.

▪You will be subject to risks associated with each of the underlyings and will be negatively affected by adverse movements in any one of the underlyings.

▪In order to obtain the modified exposure to the worst performing underlying that the securities provide, investors must be willing to accept (i) an investment that may have limited or no liquidity and (ii) the risk of not receiving any amount due under the securities if we and Citigroup Inc. default on our obligations. All payments on the securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc.

KEY TERMS
Issuer:	Citigroup Global Markets Holdings Inc., a wholly owned subsidiary of Citigroup Inc.
Guarantee:	All payments due on the securities are fully and unconditionally guaranteed by Citigroup Inc.
Underlyings:	Underlying Initial underlying value* Final buffer value** Health Care Select Sector SPDR® Fund $ $ Russell 1000® Growth Index Russell 2000® Index *For each underlying, its closing value on the pricing date **For each underlying, 75.00% of its initial underlying value
Stated principal amount:	$1,000 per security
Pricing date:	July 10, 2025
Issue date:	July 15, 2025
Valuation date:	July 16, 2026, subject to postponement if such date is not a scheduled trading day or certain market disruption events occur
Maturity date:	July 21, 2026
Payment at maturity:	You will receive at maturity for each security you then hold: ■If the final underlying value of the worst performing underlying is greater than or equal to its final buffer value: $1,000 + the digital return amount ■If the final underlying value of the worst performing underlying is less than its final buffer value: $1,000 + [$1,000 × the buffer rate × (the underlying return of the worst performing underlying + the buffer percentage)] If the final underlying value of the worst performing underlying is less than its final buffer value, which means that the worst performing underlying has depreciated from its initial underlying value by more than the buffer percentage, you will lose more than 1% of the stated principal amount of your securities at maturity for every 1% by which that depreciation exceeds the buffer percentage. Accordingly, the lower the final underlying value of the worst performing underlying, the less benefit you will receive from the buffer.
Final underlying value:	For each underlying, its closing value on the valuation date
Digital return amount:	$80.00 per security (representing a digital return equal to 8.00% of the stated principal amount). You will receive the digital return amount only if the final underlying value of the worst performing underlying is greater than or equal to its final buffer value.
Worst performing underlying:	The underlying with the lowest underlying return
Underlying return:	For each underlying, (i) its final underlying value minus its initial underlying value, divided by (ii) its initial underlying value
Buffer percentage:	25.00%
Buffer rate:	The initial underlying value of the worst performing underlying divided by its final buffer value, which is approximately 133.3333%
Listing:	The securities will not be listed on any securities exchange
CUSIP / ISIN:	17333LJK2 / US17333LJK26
Underwriter:	Citigroup Global Markets Inc. (“CGMI”), an affiliate of the issuer, acting as principal
Underwriting fee and issue price:	Issue price(1)	Underwriting fee(2)	Proceeds to issuer(3)
Per security:	$1,000.00	$2.00	$998.00
Total:	$	$	$

(1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least $941.00 per security, which will be less than the issue price. The estimated value of the securities is based on CGMI’s proprietary pricing models and our internal funding rate. It is not an indication of actual profit to CGMI or other of our affiliates, nor is it an indication of the price, if any, at which CGMI or any other person may be willing to buy the securities from you at any time after issuance. See “Valuation of the Securities” in this pricing supplement.

(2) CGMI will receive an underwriting fee of up to $2.00 for each security sold in this offering. The total underwriting fee and proceeds to issuer in the table above give effect to the actual total underwriting fee. For more information on the distribution of the securities, see “Supplemental Plan of Distribution” in this pricing supplement. In addition to the underwriting fee, CGMI and its affiliates may profit from expected hedging activity related to this offering, even if the value of the securities declines. See “Use of Proceeds and Hedging” in the accompanying prospectus.

(3) The per security proceeds to issuer indicated above represent the minimum per security proceeds to issuer for any security, assuming the maximum per security underwriting fee. As noted above, the underwriting fee is variable.

Investing in the securities involves risks not associated with an investment in conventional debt securities. See “Summary Risk Factors” beginning on page PS-5.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities or determined that this pricing supplement and the accompanying product supplement, underlying supplement, prospectus supplement and prospectus are truthful or complete. Any representation to the contrary is a criminal offense.

You should read this pricing supplement together with the accompanying product supplement, underlying supplement, prospectus supplement and prospectus, which can be accessed via the hyperlinks below:

Product Supplement No. EA-02-10 dated March 7, 2023 Underlying Supplement No. 11 dated March 7, 2023 Prospectus Supplement and Prospectus each dated March 7, 2023

The securities are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency, nor are they obligations of, or guaranteed by, a bank.

Citigroup Global Markets Holdings Inc.

Additional Information

General. The terms of the securities are set forth in the accompanying product supplement, prospectus supplement and prospectus, as supplemented by this pricing supplement. The accompanying product supplement, prospectus supplement and prospectus contain important disclosures that are not repeated in this pricing supplement. For example, the accompanying product supplement contains important information about how the closing value of each underlying will be determined and about adjustments that may be made to the terms of the securities upon the occurrence of market disruption events and other specified events with respect to each underlying. The accompanying underlying supplement contains information about each underlying that is not repeated in this pricing supplement. It is important that you read the accompanying product supplement, underlying supplement, prospectus supplement and prospectus together with this pricing supplement before deciding whether to invest in the securities. Certain terms used but not defined in this pricing supplement are defined in the accompanying product supplement.

Closing Value. The “closing value” of an underlying on any date is (i) in the case of an underlying that is an underlying index, its closing level on such date and (ii) in the case of an underlying that is an underlying ETF, the closing price of its underlying shares on such date, as provided in the accompanying product supplement. The “underlying shares” of an underlying ETF are its shares that are traded on a U.S. national securities exchange. Please see the accompanying product supplement for more information.

Payout Diagram

The diagram below illustrates your payment at maturity for a range of hypothetical underlying returns of the worst performing underlying.

Investors in the securities will not receive any dividends with respect to the underlyings. The diagram and examples below do not show any effect of lost dividend yield over the term of the securities. See “Summary Risk Factors—You will not receive dividends or have any other rights with respect to the underlyings” below.

Payout Diagram
n The Securities	n The Worst Performing Underlying

PS-2

Citigroup Global Markets Holdings Inc.

Hypothetical Examples

The examples below illustrate how to determine the payment at maturity on the securities, assuming the various hypothetical final underlying values indicated below. The examples are solely for illustrative purposes, do not show all possible outcomes and are not a prediction of what the actual payment at maturity on the securities will be. The actual payment at maturity will depend on the actual final underlying value of the worst performing underlying.

The examples below are based on the following hypothetical values and do not reflect the actual initial underlying values or final buffer values of the underlyings. For the actual initial underlying value and final buffer value of each underlying, see the cover page of this pricing supplement. We have used these hypothetical values, rather than the actual values, to simplify the calculations and aid understanding of how the securities work. However, you should understand that the actual payment at maturity on the securities will be calculated based on the actual initial underlying value and final buffer value of each underlying, and not the hypothetical values indicated below. For ease of analysis, figures below have been rounded.

Underlying	Hypothetical initial underlying value	Hypothetical final buffer value
Health Care Select Sector SPDR® Fund	$100.00	$75.00 (75.00% of its hypothetical initial underlying value)
Russell 1000® Growth Index	100.00	75.00 (75.00% of its hypothetical initial underlying value)
Russell 2000® Index	100.00	75.00 (75.00% of its hypothetical initial underlying value)

Example 1—Upside Scenario A. The final underlying value of the worst performing underlying is 105.00, resulting in a 5.00% underlying return for the worst performing underlying. In this example, the final underlying value of the worst performing underlying is greater than its final buffer value.

Underlying	Hypothetical final underlying value	Hypothetical underlying return
Health Care Select Sector SPDR® Fund*	$105.00	5.00%
Russell 1000® Growth Index	150.00	50.00%
Russell 2000® Index	150.00	50.00%

* Worst performing underlying

Payment at maturity per security = $1,000 + the digital return amount

= $1,000 + $80.00

= $1,080.00

In this scenario, because the final underlying value of the worst performing underlying is greater than its final buffer value, your total return at maturity would equal the digital return amount.

Example 2—Upside Scenario B. The final underlying value of the worst performing underlying is 180.00, resulting in a 80.00% underlying return for the worst performing underlying. In this example, the final underlying value of the worst performing underlying is greater than its final buffer value.

Underlying	Hypothetical final underlying value	Hypothetical underlying return
Health Care Select Sector SPDR® Fund	$210.00	110.00%
Russell 1000® Growth Index*	180.00	80.00%
Russell 2000® Index	200.00	100.00%

* Worst performing underlying

Payment at maturity per security = $1,000 + the digital return amount

= $1,000 + $80.00

= $1,080.00

In this scenario, because the final underlying value of the worst performing underlying is greater than its final buffer value, your total return at maturity would equal the digital return amount. In this scenario, the digital return amount is less than the underlying return of the worst performing underlying, and as a result an investment in the securities would underperform a hypothetical alternative investment providing 1-to-1 exposure to the appreciation of the worst performing underlying.

PS-3

Citigroup Global Markets Holdings Inc.

Example 3—Upside Scenario C. The final underlying value of the worst performing underlying is 90.00, resulting in a -10.00% underlying return for the worst performing underlying. In this example, the final underlying value of the worst performing underlying is less than its initial underlying value but greater than its final buffer value.

Underlying	Hypothetical final underlying value	Hypothetical underlying return
Health Care Select Sector SPDR® Fund	$110.00	10.00%
Russell 1000® Growth Index	105.00	5.00%
Russell 2000® Index*	90.00	-10.00%

* Worst performing underlying

Payment at maturity per security = $1,000 + the digital return amount

= $1,000 + $80.00

= $1,080.00

In this scenario, the worst performing underlying has depreciated from its initial underlying value to its final underlying value, but not below its final buffer value. Because the final underlying value of the worst performing underlying is greater than its final buffer value, your total return on the securities at maturity would equal the digital return amount.

Example 4—Downside Scenario A. The final underlying value of the worst performing underlying is 70.00, resulting in a -30.00% underlying return for the worst performing underlying. In this example, the final underlying value of the worst performing underlying is less than its final buffer value.

Underlying	Hypothetical final underlying value	Hypothetical underlying return
Health Care Select Sector SPDR® Fund*	$70.00	-30.00%
Russell 1000® Growth Index	150.00	50.00%
Russell 2000® Index	120.00	20.00%

* Worst performing underlying

Payment at maturity per security = $1,000 + [$1,000 × the buffer rate × (the underlying return of the worst performing underlying + the buffer percentage)]

= $1,000 + [$1,000 × 1.333333 × (-30.00% + 25.00%)]

= $1,000 + [$1,000 × 1.333333 × -5.00%]

= $1,000 + -$66.667

= $933.333

In this scenario, the worst performing underlying has depreciated from its initial underlying value to its final underlying value by more than the buffer percentage. As a result, your total return at maturity in this scenario would be negative and would reflect a loss of more than 1% of the stated principal amount of your securities (at a rate equal to the buffer rate) for every 1% by which the worst performing underlying declined beyond the buffer percentage.

Example 5—Downside Scenario B. The final underlying value of the worst performing underlying is 30.00, resulting in a -70.00% underlying return for the worst performing underlying. In this example, the final underlying value of the worst performing underlying is less than its final buffer value.

Underlying	Hypothetical final underlying value	Hypothetical underlying return
Health Care Select Sector SPDR® Fund	$40.00	-40.00%
Russell 1000® Growth Index*	30.00	-70.00%
Russell 2000® Index	170.00	70.00%

* Worst performing underlying

Payment at maturity per security = $1,000 + [$1,000 × the buffer rate × (the underlying return of the worst performing underlying + the buffer percentage)]

= $1,000 + [$1,000 × 1.333333 × (-70.00% + 25.00%)]

= $1,000 + [$1,000 × 1.333333 × -45.00%]

= $1,000 + -$600.00

= $400.00

In this scenario, the worst performing underlying has depreciated from its initial underlying value to its final underlying value by more than the buffer percentage. As a result, your total return at maturity in this scenario would be negative and would reflect a loss of more than 1% of the stated principal amount of your securities (at a rate equal to the buffer rate) for every 1% by which the worst performing underlying declined beyond the buffer percentage. A comparison of this example with the previous example illustrates the diminishing benefit of the buffer the greater the depreciation of the worst performing underlying. The greater the depreciation of the worst performing underlying, the closer your negative return on the securities will be to the depreciation of the worst performing underlying.

PS-4

Citigroup Global Markets Holdings Inc.

Summary Risk Factors

An investment in the securities is significantly riskier than an investment in conventional debt securities. The securities are subject to all of the risks associated with an investment in our conventional debt securities (guaranteed by Citigroup Inc.), including the risk that we and Citigroup Inc. may default on our obligations under the securities, and are also subject to risks associated with each underlying. Accordingly, the securities are suitable only for investors who are capable of understanding the complexities and risks of the securities. You should consult your own financial, tax and legal advisors as to the risks of an investment in the securities and the suitability of the securities in light of your particular circumstances.

The following is a summary of certain key risk factors for investors in the securities. You should read this summary together with the more detailed description of risks relating to an investment in the securities contained in the section “Risk Factors Relating to the Securities” beginning on page EA-7 in the accompanying product supplement. You should also carefully read the risk factors included in the accompanying prospectus supplement and in the documents incorporated by reference in the accompanying prospectus, including Citigroup Inc.’s most recent Annual Report on Form 10-K and any subsequent Quarterly Reports on Form 10-Q, which describe risks relating to the business of Citigroup Inc. more generally.

Citigroup Inc. will release quarterly earnings on July 15, 2025, which is after the pricing date but on the issue date of these securities.

■You may lose a significant portion or all of your investment. Unlike conventional debt securities, the securities do not repay a fixed amount of principal at maturity. Instead, your payment at maturity will depend on the performance of the worst performing underlying. If the worst performing underlying depreciates by more than the buffer percentage from its initial underlying value to its final underlying value, you will lose more than 1% of the stated principal amount of your securities for every 1% by which that depreciation exceeds the buffer percentage. You should understand that any depreciation of the worst performing underlying in excess of the buffer percentage will result in a magnified loss to your investment at a rate equal to the buffer rate, which will progressively offset any protection that the buffer percentage would offer. The lower the final underlying value, the less benefit you will receive from the buffer percentage. There is no minimum payment at maturity on the securities, and you may lose up to all of your investment.

■The securities do not pay interest. Unlike conventional debt securities, the securities do not pay interest or any other amounts prior to maturity. You should not invest in the securities if you seek current income during the term of the securities.

■Your potential return on the securities is limited. Your potential return on the securities at maturity is limited to the digital return. Your return on the securities will not exceed the digital return, even if the worst performing underlying appreciates by significantly more than the digital return. If the worst performing underlying appreciates by more than the digital return, the securities will underperform an alternative investment providing 1-to-1 exposure to the performance of the worst performing underlying. When lost dividends are taken into account, the securities may underperform an alternative investment providing 1-to-1 exposure to the performance of the worst performing underlying even if the worst performing underlying appreciates by less than the digital return.

■The securities are subject to heightened risk because they have multiple underlyings. The securities are more risky than similar investments that may be available with only one underlying. With multiple underlyings, there is a greater chance that any one underlying will perform poorly, adversely affecting your return on the securities.

■The securities are subject to the risks of each of the underlyings and will be negatively affected if any one underlying performs poorly. You are subject to risks associated with each of the underlyings. If any one underlying performs poorly, you will be negatively affected. The securities are not linked to a basket composed of the underlyings, where the blended performance of the underlyings would be better than the performance of the worst performing underlying alone. Instead, you are subject to the full risks of whichever of the underlyings is the worst performing underlying.

■You will not benefit in any way from the performance of any better performing underlying. The return on the securities depends solely on the performance of the worst performing underlying, and you will not benefit in any way from the performance of any better performing underlying.

■You will be subject to risks relating to the relationship between the underlyings. It is preferable from your perspective for the underlyings to be correlated with each other, in the sense that their closing values tend to increase or decrease at similar times and by similar magnitudes. By investing in the securities, you assume the risk that the underlyings will not exhibit this relationship. The less correlated the underlyings, the more likely it is that any one of the underlyings will perform poorly over the term of the securities. All that is necessary for the securities to perform poorly is for one of the underlyings to perform poorly. It is impossible to predict what the relationship between the underlyings will be over the term of the securities. The underlyings differ in significant ways and, therefore, may not be correlated with each other.

■You will not receive dividends or have any other rights with respect to the underlyings. You will not receive any dividends with respect to the underlyings. This lost dividend yield may be significant over the term of the securities. The payment scenarios described in this pricing supplement do not show any effect of such lost dividend yield over the term of the securities. In addition, you will not have voting rights or any other rights with respect to the underlyings or the stocks included in the underlyings.

■Your payment at maturity depends on the closing value of the worst performing underlying on a single day. Because your payment at maturity depends on the closing value of the worst performing underlying solely on the valuation date, you are subject to the risk that the closing value of the worst performing underlying on that day may be lower, and possibly significantly lower, than on one or more other dates during the term of the securities. If you had invested in another instrument linked to the worst performing underlying that you could sell for full value at a time selected by you, or if the payment at maturity were based on an average of closing values of the worst performing underlying, you might have achieved better returns.

PS-5

Citigroup Global Markets Holdings Inc.

■The securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc. If we default on our obligations under the securities and Citigroup Inc. defaults on its guarantee obligations, you may not receive anything owed to you under the securities.

■The securities will not be listed on any securities exchange and you may not be able to sell them prior to maturity. The securities will not be listed on any securities exchange. Therefore, there may be little or no secondary market for the securities. CGMI currently intends to make a secondary market in relation to the securities and to provide an indicative bid price for the securities on a daily basis. Any indicative bid price for the securities provided by CGMI will be determined in CGMI’s sole discretion, taking into account prevailing market conditions and other relevant factors, and will not be a representation by CGMI that the securities can be sold at that price, or at all. CGMI may suspend or terminate making a market and providing indicative bid prices without notice, at any time and for any reason. If CGMI suspends or terminates making a market, there may be no secondary market at all for the securities because it is likely that CGMI will be the only broker-dealer that is willing to buy your securities prior to maturity. Accordingly, an investor must be prepared to hold the securities until maturity.

■The estimated value of the securities on the pricing date, based on CGMI’s proprietary pricing models and our internal funding rate, will be less than the issue price. The difference is attributable to certain costs associated with selling, structuring and hedging the securities that are included in the issue price. These costs include (i) any selling concessions or other fees paid in connection with the offering of the securities, (ii) hedging and other costs incurred by us and our affiliates in connection with the offering of the securities and (iii) the expected profit (which may be more or less than actual profit) to CGMI or other of our affiliates in connection with hedging our obligations under the securities. These costs adversely affect the economic terms of the securities because, if they were lower, the economic terms of the securities would be more favorable to you. The economic terms of the securities are also likely to be adversely affected by the use of our internal funding rate, rather than our secondary market rate, to price the securities. See “The estimated value of the securities would be lower if it were calculated based on our secondary market rate” below.

■The estimated value of the securities was determined for us by our affiliate using proprietary pricing models. CGMI derived the estimated value disclosed on the cover page of this pricing supplement from its proprietary pricing models. In doing so, it may have made discretionary judgments about the inputs to its models, such as the volatility of, and correlation between, the closing values of the underlyings, dividend yields on the underlyings and interest rates. CGMI’s views on these inputs may differ from your or others’ views, and as an underwriter in this offering, CGMI’s interests may conflict with yours. Both the models and the inputs to the models may prove to be wrong and therefore not an accurate reflection of the value of the securities. Moreover, the estimated value of the securities set forth on the cover page of this pricing supplement may differ from the value that we or our affiliates may determine for the securities for other purposes, including for accounting purposes. You should not invest in the securities because of the estimated value of the securities. Instead, you should be willing to hold the securities to maturity irrespective of the initial estimated value.

■The estimated value of the securities would be lower if it were calculated based on our secondary market rate. The estimated value of the securities included in this pricing supplement is calculated based on our internal funding rate, which is the rate at which we are willing to borrow funds through the issuance of the securities. Our internal funding rate is generally lower than our secondary market rate, which is the rate that CGMI will use in determining the value of the securities for purposes of any purchases of the securities from you in the secondary market. If the estimated value included in this pricing supplement were based on our secondary market rate, rather than our internal funding rate, it would likely be lower. We determine our internal funding rate based on factors such as the costs associated with the securities, which are generally higher than the costs associated with conventional debt securities, and our liquidity needs and preferences. Our internal funding rate is not an interest rate that is payable on the securities.

Because there is not an active market for traded instruments referencing our outstanding debt obligations, CGMI determines our secondary market rate based on the market price of traded instruments referencing the debt obligations of Citigroup Inc., our parent company and the guarantor of all payments due on the securities, but subject to adjustments that CGMI makes in its sole discretion. As a result, our secondary market rate is not a market-determined measure of our creditworthiness, but rather reflects the market’s perception of our parent company’s creditworthiness as adjusted for discretionary factors such as CGMI’s preferences with respect to purchasing the securities prior to maturity.

■The estimated value of the securities is not an indication of the price, if any, at which CGMI or any other person may be willing to buy the securities from you in the secondary market. Any such secondary market price will fluctuate over the term of the securities based on the market and other factors described in the next risk factor. Moreover, unlike the estimated value included in this pricing supplement, any value of the securities determined for purposes of a secondary market transaction will be based on our secondary market rate, which will likely result in a lower value for the securities than if our internal funding rate were used. In addition, any secondary market price for the securities will be reduced by a bid-ask spread, which may vary depending on the aggregate stated principal amount of the securities to be purchased in the secondary market transaction, and the expected cost of unwinding related hedging transactions. As a result, it is likely that any secondary market price for the securities will be less than the issue price.

■The value of the securities prior to maturity will fluctuate based on many unpredictable factors. The value of your securities prior to maturity will fluctuate based on the closing values of the underlyings, the volatility of, and correlation between, the closing values of the underlyings, dividend yields on the underlyings, interest rates generally, the time remaining to maturity and our and Citigroup Inc.’s creditworthiness, as reflected in our secondary market rate, among other factors described under “Risk Factors Relating to the Securities—Risk Factors Relating to All Securities—The value of your securities prior to maturity will fluctuate based on many unpredictable factors” in the accompanying product supplement. Changes in the closing values of the underlyings may not result in a comparable change in the value of your securities. You should understand that the value of your securities at any time prior to maturity may be significantly less than the issue price.

■Immediately following issuance, any secondary market bid price provided by CGMI, and the value that will be indicated on any brokerage account statements prepared by CGMI or its affiliates, will reflect a temporary upward adjustment. The amount of this

PS-6

Citigroup Global Markets Holdings Inc.

temporary upward adjustment will steadily decline to zero over the temporary adjustment period. See “Valuation of the Securities” in this pricing supplement.

■The investment strategy represented by the Russell 1000^® Growth Index may not be successful.  The Russell 1000^® Growth Index is designed to measure the full performance of companies included in the Russell 1000^® Index that exhibit relatively strong growth characteristics and relatively weak value characteristics and a portion of the performance of companies with more balanced growth and value characteristics. There is, however, no assurance that the Russell 1000^® Growth Index will outperform any other index or strategy that tracks U.S. stocks selected using other criteria. A “growth” investment strategy is premised on the goal of investing in stocks of companies with relatively higher price-to-book ratios, higher I/B/E/S forecast medium term (2 year) growth and higher sales per share historical growth (5 years) on the assumption that the value of those stocks will increase over time as these companies grow more rapidly than the broader market.  However, the growth characteristics referenced by the Russell 1000^® Growth Index may not be accurate predictors of future growth, and there is no guarantee that these stocks will appreciate.  In addition, the Russell 1000^® Growth Index’s selection methodology includes a bias toward stocks that have higher prices, and if these stocks prove to be overvalued, they may underperform the broader market.  It is possible that the stock selection methodology of the Russell 1000^® Growth Index will adversely affect its return and, consequently, the level of the Russell 1000^® Growth Index and the value of your securities.

■The Health Care Select Sector SPDR^® Fund is subject to risks associated with the health care sector. All or substantially all of the securities held by the Health Care Select Sector SPDR^® Fund are issued by companies whose primary line of business is directly associated with the health care sector. As a result, the value of the securities may be subject to greater volatility and be more adversely affected by a single economic, political or regulatory occurrence affecting this sector than a different investment linked to securities of a more broadly diversified group of issuers. Companies in the health care sector are subject to extensive government regulation and their profitability can be significantly affected by restrictions on government reimbursement for medical expenses, rising costs of medical products and services, pricing pressure (including price discounting), limited product lines and an increased emphasis on the delivery of health care through outpatient services. Companies in the health care sector are heavily dependent on obtaining and defending patents, which may be time consuming and costly, and the expiration of patents may also adversely affect the profitability of these companies. Health care companies are also subject to extensive litigation based on product liability and similar claims. In addition, their products can become obsolete due to industry innovation, changes in technologies or other market developments. Many new products in the health care sector require significant research and development and may be subject to regulatory approvals, all of which may be time consuming and costly with no guarantee that any product will come to market.  These factors could affect the health care sector and could affect the value of the securities held by the Health Care Select Sector SPDR^® Fund and the value of the Health Care Select Sector SPDR^® Fund during the term of the securities, which may adversely affect the value of your securities.

■The Russell 2000^® Index is subject to risks associated with small capitalization stocks. The stocks that constitute the Russell 2000^® Index are issued by companies with relatively small market capitalization. The stock prices of smaller companies may be more volatile than stock prices of large capitalization companies. These companies tend to be less well-established than large market capitalization companies. Small capitalization companies may be less able to withstand adverse economic, market, trade and competitive conditions relative to larger companies. Small capitalization companies are less likely to pay dividends on their stocks, and the presence of a dividend payment could be a factor that limits downward stock price pressure under adverse market conditions.

■Our offering of the securities is not a recommendation of any underlying. The fact that we are offering the securities does not mean that we believe that investing in an instrument linked to the underlyings is likely to achieve favorable returns. In fact, as we are part of a global financial institution, our affiliates may have positions (including short positions) in the underlyings or in instruments related to the underlyings, and may publish research or express opinions, that in each case are inconsistent with an investment linked to the underlyings. These and other activities of our affiliates may affect the closing values of the underlyings in a way that negatively affects the value of and your return on the securities.

■The closing value of an underlying may be adversely affected by our or our affiliates’ hedging and other trading activities. We expect to hedge our obligations under the securities through CGMI or other of our affiliates, who may take positions in the underlyings or in financial instruments related to the underlyings and may adjust such positions during the term of the securities. Our affiliates also take positions in the underlyings or in financial instruments related to the underlyings on a regular basis (taking long or short positions or both), for their accounts, for other accounts under their management or to facilitate transactions on behalf of customers. These activities could affect the closing values of the underlyings in a way that negatively affects the value of and your return on the securities. They could also result in substantial returns for us or our affiliates while the value of the securities declines.

■We and our affiliates may have economic interests that are adverse to yours as a result of our affiliates’ business activities. Our affiliates engage in business activities with a wide range of companies. These activities include extending loans, making and facilitating investments, underwriting securities offerings and providing advisory services. These activities could involve or affect the underlyings in a way that negatively affects the value of and your return on the securities. They could also result in substantial returns for us or our affiliates while the value of the securities declines. In addition, in the course of this business, we or our affiliates may acquire non-public information, which will not be disclosed to you.

■The calculation agent, which is an affiliate of ours, will make important determinations with respect to the securities. If certain events occur during the term of the securities, such as market disruption events and other events with respect to an underlying, CGMI, as calculation agent, will be required to make discretionary judgments that could significantly affect your return on the securities. In making these judgments, the calculation agent’s interests as an affiliate of ours could be adverse to your interests as a holder of the securities. See “Risk Factors Relating to the Securities—Risk Factors Relating to All Securities—The calculation agent, which is an affiliate of ours, will make important determinations with respect to the securities” in the accompanying product supplement.

■In the case of an underlying that is an underlying ETF, even if the underlying pays a dividend that it identifies as special or extraordinary, no adjustment will be required under the securities for that dividend unless it meets the criteria specified in the

PS-7

Citigroup Global Markets Holdings Inc.

accompanying product supplement. In general, an adjustment will not be made under the terms of the securities for any cash dividend paid by the underlying unless the amount of the dividend per share, together with any other dividends paid in the same quarter, exceeds the dividend paid per share in the most recent quarter by an amount equal to at least 10% of the closing value of that underlying on the date of declaration of the dividend. Any dividend will reduce the closing value of the underlying by the amount of the dividend per share. If the underlying pays any dividend for which an adjustment is not made under the terms of the securities, holders of the securities will be adversely affected. See “Description of the Securities—Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF—Dilution and Reorganization Adjustments—Certain Extraordinary Cash Dividends” in the accompanying product supplement.

■In the case of an underlying that is an underlying ETF, the securities will not be adjusted for all events that may have a dilutive effect on or otherwise adversely affect the closing value of the underlying. For example, we will not make any adjustment for ordinary dividends or extraordinary dividends that do not meet the criteria described above, partial tender offers or additional underlying share issuances. Moreover, the adjustments we do make may not fully offset the dilutive or adverse effect of the particular event. Investors in the securities may be adversely affected by such an event in a circumstance in which a direct holder of the underlying shares of the underlying would not.

■In the case of an underlying that is an underlying ETF, the securities may become linked to an underlying other than the original underlying upon the occurrence of a reorganization event or upon the delisting of the underlying shares of that original underlying. For example, if the underlying enters into a merger agreement that provides for holders of its underlying shares to receive shares of another entity and such shares are marketable securities, the closing value of that underlying following consummation of the merger will be based on the value of such other shares. Additionally, if the underlying shares of the underlying are delisted, the calculation agent may select a successor underlying. See “Description of the Securities—Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF” in the accompanying product supplement.

■In the case of the underlying that is an underlying ETF, the value and performance of the underlying shares of the underlying may not completely track the performance of the underlying index that the underlying seeks to track or the net asset value per share of the underlying. In the case of the underlying that is an underlying ETF, the underlying does not fully replicate the underlying index that it seeks to track and may hold securities different from those included in its underlying index. In addition, the performance of the underlying will reflect additional transaction costs and fees that are not included in the calculation of its underlying index. All of these factors may lead to a lack of correlation between the performance of the underlying and its underlying index. In addition, corporate actions with respect to the equity securities held by the underlying (such as mergers and spin-offs) may impact the variance between the performance of the underlying and its underlying index. Finally, because the underlying shares are traded on an exchange and are subject to market supply and investor demand, the closing value of the underlying may differ from the net asset value per share of the underlying.

During periods of market volatility, securities included in the underlying’s underlying index may be unavailable in the secondary market, market participants may be unable to calculate accurately the net asset value per share of the underlying and the liquidity of the underlying may be adversely affected. This kind of market volatility may also disrupt the ability of market participants to create and redeem shares of the underlying. Further, market volatility may adversely affect, sometimes materially, the price at which market participants are willing to buy and sell the underlying shares. As a result, under these circumstances, the closing value of the underlying may vary substantially from the net asset value per share of the underlying. For all of the foregoing reasons, the performance of the underlying may not correlate with the performance of its underlying index and/or its net asset value per share, which could materially and adversely affect the value of the securities and/or reduce your return on the securities.

■Changes that affect the underlyings may affect the value of your securities. The sponsors of the underlyings may at any time make methodological changes or other changes in the manner in which they operate that could affect the values of the underlyings. We are not affiliated with any such underlying sponsor and, accordingly, we have no control over any changes any such sponsor may make. Such changes could adversely affect the performance of the underlyings and the value of and your return on the securities.

■The U.S. federal tax consequences of an investment in the securities are unclear. There is no direct legal authority regarding the proper U.S. federal tax treatment of the securities, and we do not plan to request a ruling from the Internal Revenue Service (the “IRS”). Consequently, significant aspects of the tax treatment of the securities are uncertain, and the IRS or a court might not agree with the treatment of the securities as prepaid forward contracts. If the IRS were successful in asserting an alternative treatment of the securities, the tax consequences of the ownership and disposition of the securities might be materially and adversely affected. Even if the treatment of the securities as prepaid forward contracts is respected, a security may be treated as a “constructive ownership transaction,” with potentially adverse consequences described below under “United States Federal Tax Considerations.” Moreover, future legislation, Treasury regulations or IRS guidance could adversely affect the U.S. federal tax treatment of the securities, possibly retroactively.

If you are a non-U.S. investor, you should review the discussion of withholding tax issues in “United States Federal Tax Considerations—Non-U.S. Holders” below.

You should read carefully the discussion under “United States Federal Tax Considerations” and “Risk Factors Relating to the Securities” in the accompanying product supplement and “United States Federal Tax Considerations” in this pricing supplement. You should also consult your tax adviser regarding the U.S. federal tax consequences of an investment in the securities, as well as tax consequences arising under the laws of any state, local or non-U.S. taxing jurisdiction.

PS-8

Citigroup Global Markets Holdings Inc.

Information About the Health Care Select Sector SPDR^® Fund

The Health Care Select Sector SPDR^® Fund is an exchange-traded fund that seeks to provide investment results that, before expenses, correspond generally to the performance of publicly traded equity securities of companies in the S&P Health Care Select Sector Index. The S&P Health Care Select Sector Index is intended to provide an indication of the pattern of common stock price movements of companies that are components of the S&P 500^® Index and are involved in the health care sector. The S&P Health Care Select Sector Index includes companies in the following six industries: (i) health care equipment and supplies, (ii) health care providers and services, (iii) health care technology, (iv) biotechnology, (v) pharmaceuticals and (vi) life sciences tools and services.

The Health Care Select Sector SPDR^® Fund is managed by the Select Sector SPDR^® Trust, a registered investment company. The Select Sector SPDR^® Trust consists of numerous separate investment portfolios, including the Health Care Select Sector SPDR^® Fund.

Information provided to or filed with the SEC by The Select Sector SPDR^® Trust pursuant to the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, can be located by reference to SEC file numbers 333-57791 and 811-08837, respectively, through the SEC’s website at http://www.sec.gov. In addition, information may be obtained from other sources including, but not limited to, press releases, newspaper articles and other publicly disseminated documents. The underlying shares of the Health Care Select Sector SPDR^® Fund trade on the NYSE Arca under the ticker symbol “XLV.”

Please refer to the section “Fund Descriptions— The Select Sector SPDR^® Funds” in the accompanying underlying supplement for additional information.

We have derived all information regarding the Health Care Select Sector SPDR^® Fund from publicly available information and have not independently verified any information regarding the Health Care Select Sector SPDR^® Fund. This pricing supplement relates only to the securities and not to the Health Care Select Sector SPDR^® Fund. We make no representation as to the performance of the Health Care Select Sector SPDR^® Fund over the term of the securities.

The securities represent obligations of Citigroup Global Markets Holdings Inc. (guaranteed by Citigroup Inc.) only. The sponsor of the Health Care Select Sector SPDR^® Fund is not involved in any way in this offering and has no obligation relating to the securities or to holders of the securities.

Historical Information

The closing value of the Health Care Select Sector SPDR^® Fund on July 7, 2025 was $134.36.

The graph below shows the closing value of the Health Care Select Sector SPDR^® Fund for each day such value was available from January 2, 2015 to July 7, 2025. We obtained the closing values from Bloomberg L.P., without independent verification. You should not take historical closing values as an indication of future performance.

Health Care Select Sector SPDR^® Fund – Historical Closing Values January 2, 2015 to July 7, 2025

PS-9

Citigroup Global Markets Holdings Inc.

Information About the Russell 1000^® Growth Index

The Russell 1000^® Growth Index aims to measure the performance of the large-cap growth segment of the U.S. equity universe.

Please refer to Annex A to this pricing supplement for additional information.

Historical Information

The closing value of the Russell 1000^® Growth Index on July 7, 2025 was 4,281.408.

The graph below shows the closing value of the Russell 1000® Growth Index for each day such value was available from January 2, 2015 to July 7, 2025. We obtained the closing values from Bloomberg L.P., without independent verification. You should not take historical closing values as an indication of future performance.

Russell 1000^® Growth Index – Historical Closing Values January 2, 2015 to July 7, 2025

PS-10

Citigroup Global Markets Holdings Inc.

Information About the Russell 2000^® Index

The Russell 2000^® Index is designed to track the performance of the small capitalization segment of the U.S. equity market. All stocks included in the Russell 2000^® Index are traded on a major U.S. exchange. It is calculated and maintained by FTSE Russell.

Please refer to the section “Equity Index Descriptions— The Russell Indices” in the accompanying underlying supplement for additional information.

We have derived all information regarding the Russell 2000^® Index from publicly available information and have not independently verified any information regarding the Russell 2000^® Index. This pricing supplement relates only to the securities and not to the Russell 2000^® Index. We make no representation as to the performance of the Russell 2000^® Index over the term of the securities.

The securities represent obligations of Citigroup Global Markets Holdings Inc. (guaranteed by Citigroup Inc.) only. The sponsor of the Russell 2000^® Index is not involved in any way in this offering and has no obligation relating to the securities or to holders of the securities.

Historical Information

The closing value of the Russell 2000^® Index on July 7, 2025 was 2,214.226.

The graph below shows the closing value of the Russell 2000^® Index for each day such value was available from January 2, 2015 to July 7, 2025. We obtained the closing values from Bloomberg L.P., without independent verification. You should not take historical closing values as an indication of future performance.

Russell 2000^® Index – Historical Closing Values January 2, 2015 to July 7, 2025

PS-11

Citigroup Global Markets Holdings Inc.

United States Federal Tax Considerations

You should read carefully the discussion under “United States Federal Tax Considerations” and “Risk Factors Relating to the Securities” in the accompanying product supplement and “Summary Risk Factors” in this pricing supplement.

There are no statutory, judicial or administrative authorities that address the U.S. federal income tax treatment of the securities or instruments that are similar to the securities. In the opinion of our counsel, Davis Polk & Wardwell LLP, it is more likely than not that a security will be treated as a prepaid forward contract for U.S. federal income tax purposes. By purchasing a security, you agree (in the absence of an administrative determination or judicial ruling to the contrary) to this treatment. There is uncertainty regarding this treatment, and the IRS or a court might not agree with it. Moreover, our counsel’s opinion is based on market conditions as of the date of this preliminary pricing supplement and is subject to confirmation on the pricing date.

Assuming this treatment of the securities is respected and subject to the discussion in “United States Federal Tax Considerations” in the accompanying product supplement, the following U.S. federal income tax consequences should result under current law:

●You should not recognize taxable income over the term of the securities prior to maturity, other than pursuant to a sale or exchange.

●Upon a sale or exchange of a security (including retirement at maturity), you should recognize gain or loss equal to the difference between the amount realized and your tax basis in the security. Subject to the discussion below concerning the potential application of the “constructive ownership” rules under Section 1260 of the Code, any gain or loss recognized upon a sale, exchange or retirement of a security should be long-term capital gain or loss if you held the security for more than one year.

Even if the treatment of the securities as prepaid forward contracts is respected, your purchase of a security may be treated as entry into a “constructive ownership transaction,” within the meaning of Section 1260 of the Code. In that case, all or a portion of any long-term capital gain you would otherwise recognize in respect of your securities would be recharacterized as ordinary income to the extent such gain exceeded the “net underlying long-term capital gain.” Any long-term capital gain recharacterized as ordinary income under Section 1260 would be treated as accruing at a constant rate over the period you held your securities, and you would be subject to an interest charge in respect of the deemed tax liability on the income treated as accruing in prior tax years. Due to the lack of governing authority under Section 1260, our counsel is not able to opine as to whether or how Section 1260 applies to the securities. You should read the section entitled “United States Federal Tax Considerations—Tax Consequences to U.S. Holders—Securities Treated as Prepaid Forward Contracts—Possible Application of Section 1260 of the Code” in the accompanying product supplement for additional information and consult your tax adviser regarding the potential application of the “constructive ownership” rule.

We do not plan to request a ruling from the IRS regarding the treatment of the securities. An alternative characterization of the securities could materially and adversely affect the tax consequences of ownership and disposition of the securities, including the timing and character of income recognized. In addition, the U.S. Treasury Department and the IRS have requested comments on various issues regarding the U.S. federal income tax treatment of “prepaid forward contracts” and similar financial instruments and have indicated that such transactions may be the subject of future regulations or other guidance. Furthermore, members of Congress have proposed legislative changes to the tax treatment of derivative contracts. Any legislation, Treasury regulations or other guidance promulgated after consideration of these issues could materially and adversely affect the tax consequences of an investment in the securities, possibly with retroactive effect. You should consult your tax adviser regarding possible alternative tax treatments of the securities and potential changes in applicable law.

Non-U.S. Holders. Subject to the discussions below and in “United States Federal Tax Considerations” in the accompanying product supplement, if you are a Non-U.S. Holder (as defined in the accompanying product supplement) of the securities, you generally should not be subject to U.S. federal withholding or income tax in respect of any amount paid to you with respect to the securities, provided that (i) income in respect of the securities is not effectively connected with your conduct of a trade or business in the United States, and (ii) you comply with the applicable certification requirements.

As discussed under “United States Federal Tax Considerations—Tax Consequences to Non-U.S. Holders” in the accompanying product supplement, Section 871(m) of the Code and Treasury regulations promulgated thereunder (“Section 871(m)”) generally impose a 30% withholding tax on dividend equivalents paid or deemed paid to Non-U.S. Holders with respect to certain financial instruments linked to U.S. equities (“U.S. Underlying Equities”) or indices that include U.S. Underlying Equities. Section 871(m) generally applies to instruments that substantially replicate the economic performance of one or more U.S. Underlying Equities, as determined based on tests set forth in the applicable Treasury regulations. However, the regulations, as modified by an IRS notice, exempt financial instruments issued prior to January 1, 2027 that do not have a “delta” of one. Based on the terms of the securities and representations provided by us as of the date of this preliminary pricing supplement, our counsel is of the opinion that the securities should not be treated as transactions that have a “delta” of one within the meaning of the regulations with respect to any U.S. Underlying Equity and, therefore, should not be subject to withholding tax under Section 871(m). However, the final determination regarding the treatment of the securities under Section 871(m) will be made as of the pricing date for the securities, and it is possible that the securities will be subject to withholding tax under Section 871(m) based on the circumstances as of that date.

A determination that the securities are not subject to Section 871(m) is not binding on the IRS, and the IRS may disagree with this treatment. Moreover, Section 871(m) is complex and its application may depend on your particular circumstances, including your other transactions. You should consult your tax adviser regarding the potential application of Section 871(m) to the securities.

If withholding tax applies to the securities, we will not be required to pay any additional amounts with respect to amounts withheld.

You should read the section entitled “United States Federal Tax Considerations” in the accompanying product supplement. The preceding discussion, when read in combination with that section, constitutes the full opinion of Davis Polk & Wardwell LLP regarding the material U.S. federal tax consequences of owning and disposing of the securities.

You should also consult your tax adviser regarding all aspects of the U.S. federal income and estate tax consequences of an investment in the securities and any tax consequences arising under the laws of any state, local or non-U.S. taxing jurisdiction.

PS-12

Citigroup Global Markets Holdings Inc.

Supplemental Plan of Distribution

CGMI, an affiliate of Citigroup Global Markets Holdings Inc. and the underwriter of the sale of the securities, is acting as principal and will receive an underwriting fee of up to $2.00 for each security sold in this offering. The actual underwriting fee will be equal to the selling concession provided to selected dealers, as described in this paragraph. From this underwriting fee, CGMI will pay selected dealers not affiliated with CGMI a variable selling concession of up to $2.00 for each security they sell.

See “Plan of Distribution; Conflicts of Interest” in the accompanying product supplement and “Plan of Distribution” in each of the accompanying prospectus supplement and prospectus for additional information.

Valuation of the Securities

CGMI calculated the estimated value of the securities set forth on the cover page of this pricing supplement based on proprietary pricing models. CGMI’s proprietary pricing models generated an estimated value for the securities by estimating the value of a hypothetical package of financial instruments that would replicate the payout on the securities, which consists of a fixed-income bond (the “bond component”) and one or more derivative instruments underlying the economic terms of the securities (the “derivative component”). CGMI calculated the estimated value of the bond component using a discount rate based on our internal funding rate. CGMI calculated the estimated value of the derivative component based on a proprietary derivative-pricing model, which generated a theoretical price for the instruments that constitute the derivative component based on various inputs, including the factors described under “Summary Risk Factors—The value of the securities prior to maturity will fluctuate based on many unpredictable factors” in this pricing supplement, but not including our or Citigroup Inc.’s creditworthiness. These inputs may be market-observable or may be based on assumptions made by CGMI in its discretionary judgment.

The estimated value of the securities is a function of the terms of the securities and the inputs to CGMI’s proprietary pricing models.  As of the date of this preliminary pricing supplement, it is uncertain what the estimated value of the securities will be on the pricing date because it is uncertain what the values of the inputs to CGMI’s proprietary pricing models will be on the pricing date.

For a period of approximately three months following issuance of the securities, the price, if any, at which CGMI would be willing to buy the securities from investors, and the value that will be indicated for the securities on any brokerage account statements prepared by CGMI or its affiliates (which value CGMI may also publish through one or more financial information vendors), will reflect a temporary upward adjustment from the price or value that would otherwise be determined. This temporary upward adjustment represents a portion of the hedging profit expected to be realized by CGMI or its affiliates over the term of the securities. The amount of this temporary upward adjustment will decline to zero on a straight-line basis over the three-month temporary adjustment period. However, CGMI is not obligated to buy the securities from investors at any time.  See “Summary Risk Factors—The securities will not be listed on any securities exchange and you may not be able to sell them prior to maturity.”

Contact

Clients may contact their local brokerage representative. Third-party distributors may contact Citi Structured Investment Sales at (212) 723-7005.

© 2025 Citigroup Global Markets Inc. All rights reserved. Citi and Citi and Arc Design are trademarks and service marks of Citigroup Inc. or its affiliates and are used and registered throughout the world.

PS-13

Citigroup Global Markets Holdings Inc.

Annex A
Description of the Russell 1000^® Growth Index

The Russell 1000^® Growth Index is calculated, published and disseminated by FTSE Russell, a subsidiary of the London Stock Exchange Group plc (“LSE”).  All information contained in this pricing supplement regarding the Russell 1000^® Growth Index has been derived from information provided by FTSE Russell, without independent verification.  This information reflects the policies of, and is subject to change by, FTSE Russell.  FTSE Russell has no obligation to continue to publish, and may discontinue publication of, the Russell 1000^® Growth Index.  The securities represent obligations of Citigroup Global Markets Holdings Inc. (guaranteed by Citigroup Inc.) only.  FTSE Russell is not involved in any way in this offering and has no obligation relating to the securities or to holders of the securities.

The Russell 1000^® Growth Index aims to measure the performance of the large-cap growth segment of the U.S. equity universe. It includes those Russell 1000^® Index companies with relatively higher price-to-book ratios, higher I/B/E/S forecast medium term (2 year) growth and higher sales per share historical growth (5 years).  The Russell 1000^® Index is designed to track the performance of the large-capitalization segment of the U.S. equity market and is composed of the 1,000 largest securities that form the Russell 3000^® Index.  The Russell 3000^® Index is composed of the 3,000 largest U.S. companies as determined by market capitalization and represents approximately 98% of the U.S. equity market.

The Russell 1000^® Growth Index is reported by Bloomberg L.P. under the ticker symbol “RLG.”

Russell 1000^® Growth Index Construction and Calculation

Selection of stocks underlying the Russell 1000^® Growth Index.

The Russell 1000^® Growth Index is a sub-group of the Russell 1000^® Index.  To be eligible for inclusion in the Russell 1000^® Index, and, consequently, the Russell 1000^® Growth Index, a company’s stocks must be listed on the last trading day in May of a given year and FTSE Russell must have access to documentation verifying the company’s eligibility for inclusion.  Beginning September 2004, eligible initial public offerings are added to Russell U.S. Indices at the end of each calendar quarter, based on total market capitalization rankings within the market-adjusted capitalization breaks established during the most recent reconstitution.  To be added to any Russell U.S. equity index during a quarter outside of reconstitution, initial public offerings must meet additional eligibility criteria.  As of August 2020, to be eligible for inclusion in the Russell 1000^® Growth Index, each company is required to have more than 5% of its voting rights (aggregated across all of its equity securities) held by unrestricted shareholders. Shares referenced as “non-voting” or providing legally minimum rights only will be viewed as having no voting power as it relates to the minimum voting rights review. Companies already included in the Russell 1000^® Growth Index have a grandfathering period to comply with this requirement, or they will be removed from the Russell 1000^® Growth Index in September 2022.

Only companies that are determined to be part of the U.S. equity market are eligible for inclusion in the Russell 1000^® Growth Index.  All securities eligible for inclusion must trade on a major U.S. exchange. Bulletin board, pink sheet or over-the-counter traded securities are not eligible for inclusion.  Stocks must have a close price at or above $1.00 on their primary exchange or on another major U.S. exchange on the last trading day in May to be considered eligible for inclusion.  The following companies are specifically excluded from the Russell 1000^® Growth Index: (i) companies with a total market capitalization less than $30 million; (ii) companies with only a small portion of their shares available in the marketplace; (iii) royalty trusts, limited liability companies, closed-end investment companies (companies that are required to report Acquired Fund Fees and Expenses, as defined by the Securities and Exchange Commission, including business development companies, are not eligible for inclusion), blank check companies, special purpose acquisition companies, limited partnerships, exchange-traded funds and mutual funds. In addition, preferred and convertible preferred stock, redeemable shares, participating preferred stock, warrants, rights and trust receipts are not eligible for inclusion.

FTSE Russell uses a “non-linear probability” method to assign stocks to the growth and value style indices.  The term “probability” is used to indicate the degree of certainty that a stock is value or growth based on its relative book-to-price (B/P) ratio, I/B/E/S forecast medium-term growth (2 year) and sales per share historical growth (5 year).  This method allows stocks to be represented as having both growth and value characteristics, while preserving the additive nature of the indices.

The process for assigning growth and value weights is applied separately to the stocks in the Russell 1000^® Index.  The stocks in the Russell 1000^® Index are ranked by their adjusted book-to-price ratio (B/P), their I/B/E/S forecast medium-term growth (2 year) and sales per share historical growth (5 year).  These rankings are converted to standardized units and combined to produce a Composite Value Score (“CVS”).  Stocks are then ranked by their CVS, and a probability algorithm is applied to the CVS distribution to assign growth and value weights to each stock.  In general, stocks with a lower CVS are considered growth, stocks with a higher CVS are considered value, and stocks with a CVS in the middle range are considered to have both growth and value characteristics, and are weighted proportionately in the growth and value index.  Stocks are always fully represented by the combination of their growth and value weights, e.g., a stock that is given a 20% weight in a Russell value index will have an 80% weight in the same Russell growth index.

Stock A, in the figure below, is a security with 20% of its available shares assigned to the value index and the remaining 80% assigned to the growth index.  The growth and value probabilities will always sum to 100%.  Hence, the sum of a stock’s market capitalization in the growth and value index will always equal its market capitalization in the Russell 1000^® Index.

PS-14

Citigroup Global Markets Holdings Inc.

In the figure above, the quartile breaks are calculated such that approximately 25% of the available market capitalization lies in each quartile.  Stocks at the median are divided 50% in each style index.  Stocks below the first quartile are 100% in the growth index.  Stocks above the third quartile are 100% in the value index.  Stocks falling between the first and third quartile breaks are in both indexes to varying degrees depending on how far they are above or below the median and how close they are to the first or third quartile breaks.

Roughly 70% of the available market capitalization is classified as all growth or all value.  The remaining 30% have some portion of their market value in either the value or growth index, depending on their relative distance from the median value score.  Note that there is a small position cutoff rule.  If a stock’s weight is more than 95% in one style index, its weight is increased to 100% in the index. 

In an effort to mitigate unnecessary turnover, FTSE Russell implements a banding methodology at the CVS level of the growth and value style algorithm. If a company’s CVS change from the previous year is greater than or equal to +/- 0.10 and if the company remains in the same base index, then the CVS remains unchanged during the next reconstitution process. Keeping the CVS static for these companies does not mean the probability (growth/value) will remain unchanged in all cases due to the relation of a CVS score to the overall index. However, this banding methodology is intended to reduce turnover caused by smaller, less meaningful movements while continuing to allow the larger, more meaningful changes to occur, signaling a true change in a company’s relation to the market.

In calculating growth and value weights, stocks with missing or negative values for B/P, or missing values for I/B/E/S growth, or missing sales per share historical growth (6 years of quarterly numbers are required), are allocated by using the mean value score of the Russell Global Sectors industry, subsector or sector group into which the company falls. Each missing (or negative B/P) variable is substituted with the industry, subsector or sector group independently. An industry must have five members or the substitution reverts to the subsector, and so forth to the sector. In addition, a weighted value score is calculated for securities with low analyst coverage for I/B/E/S medium-term growth. For securities with coverage by a single analyst, 2/3 of the industry, subsector, or sector group value score is weighted with 1/3 the security’s independent value score. For those securities with coverage by two analysts, 2/3 of the independent security’s value score is used and only 1/3 of the industry, subsector, or sector group is weighted. For those securities with at least three analysts contributing to the I/B/E/S medium-term growth, 100% of the independent security’s value score is used.

The Russell 1000^® Growth Index, along with the Russell 1000^® Index, is reconstituted annually to reflect changes in the marketplace.  The list of companies is ranked based on May 31 total market capitalization, with the actual reconstitution effective on the first trading day following the final Friday of June each year.  Changes in the constituents are preannounced and subject to change if any corporate activity occurs or if any new information is received prior to release.

Capitalization Adjustments.

The Russell 1000^® Growth Index is a float-adjusted and market-capitalization weighted index.  The current Russell 1000^® Growth Index value is calculated by adding the market values of the Russell 1000^® Index’s Component Stocks, which are derived by multiplying the price of each stock by the number of available shares, to arrive at the total market capitalization of the 1,000 stocks.  The total market capitalization is then divided by a divisor, which represents the “adjusted” capitalization of the Russell 1000^® Growth Index on the base date of January 1, 1987.  To calculate the Russell 1000^® Growth Index, last sale prices will be used for exchange-traded stocks.  If a component stock is not open for trading, the most recently traded price for that security will be used in calculating the Russell 1000^® Growth Index.  In order to provide continuity for the Russell 1000^® Growth Index’s value, the divisor is adjusted periodically to reflect events including changes in the number of common shares outstanding for Russell 1000 Component Stocks, company additions or deletions, corporate restructurings and other capitalization changes.

Available shares are assumed to be shares available for trading.  Exclusion of capitalization held by directors, senior executives and managers of the company is based on information recorded in corporate filings with the Securities and Exchange Commission.  Where FTSE Russell determines that a company is being excluded from index membership solely on the basis of the minimum float requirement, FTSE Russell will use the best available information contained in the Securities and Exchange Commission filings to determine the free float.

The following types of shares are considered unavailable and are removed from total market capitalization to arrive at free float or available market capitalization:

●ESOP or LESOP shares – Shares held within employee share plans;

PS-15

Citigroup Global Markets Holdings Inc.

●Public company holdings – Shares held by public companies or by non-listed subsidiaries of public companies;

●Lock-In clause shares – All Shares where the holders is subject to a lock-in clause are considered unavailable for the duration of the lock-in clause. Free Float changes resulting from the expiry of a lock-in will be implemented at the next quarterly review, subject to the lock-in or incentive expiry date occurring on or prior to the share and float change information cut-off date;

●Active participation or strategic holding shares – Shares held by an investor, investment company or an investment fund that is actively participating in the management of a company or is holding shares in a company for strategic reasons as evidenced by specific statements to that effect in publicly available announcements, or has successfully placed a current member to the board of directors of a company;

●On-going contractual agreement shares – Shares that are subject to ongoing contractual agreements (such as swaps) where they would ordinarily be treated as restricted are considered unavailable;

●Sovereign Wealth Fund shares – Shares held by a Sovereign Wealth Fund are considered unavailable where the Sovereign Wealth Fund’s owns 10% or more of the shares;

●Corporate insider shares – Corporate insider shares are defined as those shares held by founders, promoters, former directors, founding venture capital and private equity firms, private companies, and individuals (including employees) and shares held by several investors acting in concert that own 10% or more of the shares outstanding. Portfolio holdings (such as pension fund, insurance fund or investment companies) are generally not considered unavailable. However, where a single portfolio holding is 30% or greater it will be regarded as strategic and therefore unavailable;

●Legally restricted shares – Legally restricted shares are defined as shares where the company’s shareholders are subject to legal restrictions, including foreign ownership restrictions, that are more restrictive; and

●Government holdings:

●Direct government holders – Shares directly owned by State, Regional, Municipal and Local Governments are considered unavailable and will be removed entirely from available shares;

●Indirect government holders  – shares held by government investment boards and/or investment arms will be treated similar to portfolio holdings and removed if the holding is greater than 30%; and

●Government pensions – holdings by independently managed pension schemes for governments are considered institutional holdings and will not be removed from available shares.

Corporate Actions Affecting the Russell 1000^® Growth Index.

The following summarizes the types of Russell 1000^® Growth Index maintenance adjustments and indicates whether or not an index adjustment is required:

●“No Replacement” Rule – Securities that leave the Russell 1000^® Growth Index, between reconstitution dates, for any reason (e.g., mergers, acquisitions or other similar corporate activity) are not replaced.  Thus, the number of securities in the Russell 1000^® Growth Index over the past year will fluctuate according to corporate activity.

●Rule for Deletions – When a stock is acquired, delisted, or moves to the pink sheets or bulletin boards on the floor of a U.S. securities exchange, the stock is deleted from the index at the close on the effective date or when the stock is no longer trading on the exchange.

●When acquisitions or mergers take place within the Russell 1000^® Growth Index, the stock’s capitalization moves to the acquiring stock, hence, mergers have no effect on the index total capitalization.  Shares are updated for the acquiring stock at the time the transaction is final.

●Rule for Additions – The only additions between reconstitution dates are as a result of spin-offs and initial public offerings.  Spin-off companies are added to the parent company’s index and capitalization tier of membership (i) until the next annual reconstitution date, if the spin-off company is eligible for the Russell 1000^® Index or (ii) for two business days, if the spin-off company is ineligible for the Russell 1000^® Index.

Updates to Share Capital Affecting the Russell 1000^® Growth Index.

In March, June, September, and December, the Russell 1000^® Growth Index is updated for changes to shares outstanding as companies report changes in share capital to the Securities and Exchange Commission.  The changes will be implemented quarterly, on the third Friday of the month (after the close). In June, any change to shares outstanding will be implemented. In March, September, and December, only cumulative changes to shares outstanding greater than 3% will be reflected in the Russell 1000^® Growth Index.  This does not affect treatment of major corporate events, which are effective on the ex-date.

PS-16

Citigroup Global Markets Holdings Inc.

License Agreement

“Russell 1000^® Growth Index” is a trademark of LSE and has been licensed for use by Citigroup Global Markets Inc. and its affiliates. This transaction is not sponsored, endorsed, sold, or promoted by LSE and LSE makes no representation regarding the advisability of entering into this transaction.

LSE DOES NOT GUARANTEE THE ACCURACY AND/OR THE COMPLETENESS OF THE RUSSELL 1000^® GROWTH INDEX OR ANY DATA INCLUDED THEREIN AND FTSE RUSSELL SHALL HAVE NO LIABILITY FOR ANY ERRORS, OMISSIONS, OR INTERRUPTIONS THEREIN. LSE MAKES NO WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY CITIGROUP INC. AND/OR ITS AFFILIATES, INVESTORS, OWNERS OF THE SECURITIES, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE RUSSELL 1000^® GROWTH INDEX OR ANY DATA INCLUDED THEREIN. LSE MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE RUSSELL 1000^® GROWTH INDEX OR ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL RUSSELL HAVE ANY LIABILITY FOR ANY SPECIAL, PUNITIVE, INDIRECT, OR CONSEQUENTIAL DAMAGES (INCLUDING LOST PROFITS), EVEN IF NOTIFIED OF THE POSSIBILITY OF THEREOF. THERE ARE NO THIRD PARTY BENEFICIARIES OF ANY AGREEMENTS OR ARRANGEMENTS BETWEEN RUSSELL AND CITIGROUP INC.”

The “Russell 1000^® Index” is a trademark of FTSE Russell.  The securities are not sponsored, endorsed, sold or promoted by FTSE Russell and FTSE Russell makes no representation regarding the advisability of investing in the securities.

PS-17

FAQ

How many ServiceTitan (TTAN) shares are proposed for sale in the new Form 144?

The notice covers 390 Class A common shares with an aggregate market value of $42,705.

Who is executing the upcoming TTAN share sale?

The broker listed is Merrill Lynch, Pierce, Fenner & Smith Incorporated, San Francisco.

How many TTAN shares were sold in the past 3 months by insiders?

VC entities linked to Bessemer Venture Partners and 15 Angels II LLC sold roughly 931,364 shares between 10 June 2025 and 03 July 2025.

What percentage of TTAN's outstanding shares have been sold recently?

The 931,364 shares sold represent approximately 16% of the 5,770,464 shares outstanding as stated in the filing.

What were the total gross proceeds from recent insider TTAN sales?

Recent insider transactions generated about $97.6 million in gross proceeds.

Does the Form 144 mention any undisclosed negative information about ServiceTitan?

No. The signer affirms they are unaware of any material adverse information not already public, per Rule 144 requirements.