[424B2] Citigroup Inc. Prospectus Supplement

Rhea-AI Filing Summary

JPMorgan Chase Financial Company LLC is offering $8.432 million of unsecured, unsubordinated Trigger GEARS (Growth Enhanced Asset Return Securities) linked to the EURO STOXX 50 Index, fully and unconditionally guaranteed by JPMorgan Chase & Co. The notes trade on a $10 denomination, settle on 30 June 2025 and mature on 28 June 2030.

Pay-off profile: if the index return is positive, investors receive principal plus 1.93 × the index appreciation (Upside Gearing). If the return is zero or negative but the final level remains at or above 75 % of the initial level (3,933.02 versus the initial 5,244.03), principal is merely repaid. A final level below the 75 % threshold exposes holders to a one-for-one loss, potentially down to a total loss of principal.

Economics: the public price is $10.00; UBS earns a $0.35 selling commission, leaving net proceeds of $9.65. JPMorgan’s estimated value is $9.561, implying embedded costs of roughly 4.4 % of face value. The notes pay no coupons, confer no dividends and will not be exchange-listed, limiting secondary-market liquidity.

Risk considerations: investors bear (i) market risk of the EURO STOXX 50, (ii) issuer and guarantor credit risk, and (iii) liquidity risk from the lack of listing. The contingent repayment of principal applies only at maturity; early sale may result in prices well below issue value. The securities are therefore significantly riskier than conventional debt instruments.

Prospective purchasers should review the detailed Key Risks and related prospectus documents referenced in the filing before investing.

Positive

• Leveraged upside of 1.93× offers enhanced participation in any EURO STOXX 50 gains.
• Contingent principal protection up to a 25 % decline provides limited buffer against moderate market drops.

Negative

• Full downside exposure below the 75 % threshold can lead to 100 % loss of principal.
• No coupons or dividends; return depends solely on index level at maturity.
• Credit risk of JPMorgan Chase Financial Company LLC and JPMorgan Chase & Co. adds a second layer of risk.
• Estimated fair value ($9.561) is 4.4 % below issue price, indicating meaningful embedded costs.
• No exchange listing limits liquidity and may force holders to accept significant discounts if sold before maturity.

Insights

Structured-Products Analyst

TL;DR: Leveraged upside (1.93×) with 25 % buffer, but full downside beyond and 4.4 % embedded costs.

The filing describes a routine structured-note issuance rather than a corporate event. For yield-seeking investors, the 1.93 gearing is attractive; however, the 75 % buffer is modest given a 5-year tenor and Europe-centric equity exposure. The estimated value shows a 43.9 bp annual drag versus issue price, reflecting fees and hedging costs. With no coupons or dividends, total return hinges entirely on index level at maturity. Credit exposure to JPMorgan is investment-grade, but still adds a second risk dimension. Overall, the security suits tactical investors comfortable with equity risk and illiquidity, but offers no clear advantage versus plain index exposure minus dividends.

Risk Analyst

TL;DR: Contingent protection is thin; investors face high downside and issuer credit risk.

While marketed as "buffered," the note absorbs only the first 25 % decline; a deeper bear market quickly erodes principal at a 1:1 rate. Given historical EURO STOXX 50 drawdowns of 50–60 %, total loss is plausible. Lack of exchange listing amplifies liquidity premiums, and secondary pricing will embed issuer funding costs and volatility shifts. The issuer/guarantor are strong credits, but structured-product holders are senior unsecured claimants, ranking pari passu with other debt. The commission structure (3.5 % of face) plus residual hedging spread explains most of the gap between price and estimated value. Risk-adjusted, the product is unlikely to outperform a financed index position with stop-loss discipline.

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, 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 JUNE 30, 2025

Citigroup Global Markets Holdings Inc.

June     , 2025 Medium-Term Senior Notes, Series N Pricing Supplement No. 2025-USNCH27438 Filed Pursuant to Rule 424(b)(2) Registration Statement Nos. 333-270327 and 333-270327-01

Enhanced Barrier Digital Securities Linked to Constellation Energy Corporation Due August 4, 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 with a value that may be greater than or less than the stated principal amount, depending on the performance of the underlying specified below from the initial underlying value to the final underlying value.

▪The securities offer modified exposure to the performance of the underlying, with a digital (fixed) return at maturity so long as the final underlying value is greater than or equal to the final barrier value. In exchange, investors in the securities must be willing to forgo (i) any appreciation of the underlying in excess of the digital return and (ii) any dividends with respect to the underlying. In addition, investors in the securities must be willing to accept full downside exposure to the depreciation of the underlying if the final underlying value is less than the final barrier value. If the final underlying value is less than the final barrier value, you will not be repaid the stated principal amount of your securities at maturity and, instead, will receive underlying shares of the underlying (or, in our sole discretion, cash based on the value thereof) that will be worth significantly less than your initial investment and possibly worth nothing. You may lose your entire investment in the securities.

▪In order to obtain the modified exposure to the 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.
Underlying:	Constellation Energy Corporation
Stated principal amount:	$1,000 per security
Pricing date:	June 30, 2025
Issue date:	July 7, 2025
Valuation date:	July 30, 2026, subject to postponement if such date is not a scheduled trading day or certain market disruption events occur
Maturity date:	August 4, 2026
Payment at maturity:	You will receive at maturity for each security you then hold: ■If the final underlying value is greater than or equal to the final barrier value: $1,000 + the digital return amount ■If the final underlying value is less than the final barrier value: a fixed number of underlying shares of the underlying equal to the equity ratio (or, if we elect, the cash value of those shares based on the final underlying value) If the final underlying value is less than the final barrier value, you will receive underlying shares (or, in our sole discretion, cash) that will be worth significantly less than the stated principal amount of your securities, and possibly nothing, at maturity.
Initial underlying value:	$, the closing value of the underlying on the pricing date
Final underlying value:	The closing value of the underlying on the valuation date
Final barrier value:	$, 54.00% of the initial underlying value
Equity ratio:	, the stated principal amount divided by the initial underlying value
Digital return amount:	$150.00 per security (representing a digital return equal to 15.00% of the stated principal amount). You will receive the digital return amount only if the final underlying value is greater than or equal to the final barrier value.
Underlying return:	(i) The final underlying value minus the initial underlying value, divided by (ii) the initial underlying value
Listing:	The securities will not be listed on any securities exchange
CUSIP / ISIN:	17333H7D0 / US17333H7D00
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	$11.00	$989.00
Total:	$	$	$

(1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least $928.00 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 $11.00 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. From this underwriting fee, CGMI will pay selected dealers not affiliated with CGMI a selling concession of $10.00 for each security they sell and a structuring fee of up to $1.00 for each security they sell. 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, 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, prospectus supplement and prospectus, which can be accessed via the hyperlinks below:

Product Supplement No. EA-02-10 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 the 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 the underlying. It is important that you read the accompanying product 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 the underlying on any date is the closing price of its underlying shares on such date, as provided in the accompanying product supplement. The “underlying shares” of the underlying are its shares of common stock. Please see the accompanying product supplement for more information.

Payout Diagram

The diagram below illustrates the value of what you would receive at maturity for a range of hypothetical underlying returns. For purposes of the diagram, the value of any underlying shares you receive at maturity is based on the final underlying value, which is the closing value of the underlying on the valuation date. On the maturity date, the value of any underlying shares you receive may differ from their value on the valuation date.

Investors in the securities will not receive any dividends with respect to the underlying. 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 underlying unless and until you receive underlying shares of the underlying at maturity” below.

Payout Diagram
n The Securities	n The 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.

The examples below are based on the following hypothetical values and do not reflect the actual initial underlying value, final barrier value or equity ratio. For the actual initial underlying value, final barrier value and equity ratio, 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 what you actually receive at maturity will be determined based on the actual initial underlying value, final barrier value and equity ratio, and not the hypothetical values indicated below. For ease of analysis, figures below have been rounded.

Hypothetical initial underlying value:	$100.00
Hypothetical final barrier value:	$54.00 (54.00% of the hypothetical initial underlying value)
Hypothetical equity ratio:	10.00000 (the stated principal amount divided by the hypothetical initial underlying value)

Example 1—Upside Scenario A. The final underlying value is $105.00, resulting in a 5.00% underlying return. In this example, the final underlying value is greater than the final barrier value.

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

= $1,000 + $150.00

= $1,150.00

In this scenario, because the final underlying value is greater than the final barrier value, your total return at maturity would equal the digital return amount.

Example 2—Upside Scenario B. The final underlying value is $180.00, resulting in a 80.00% underlying return. In this example, the final underlying value is greater than the final barrier value.

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

= $1,000 + $150.00

= $1,150.00

In this scenario, because the final underlying value is greater than the final barrier 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, 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 underlying.

Example 3—Upside Scenario C. The final underlying value is $90.00, resulting in a -10.00% underlying return. In this example, the final underlying value is greater than the final barrier value.

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

= $1,000 + $150.00

= $1,150.00

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

Example 4—Downside Scenario A. The final underlying value is $30.00, resulting in a -70.00% underlying return. In this example, the final underlying value is less than the final barrier value.

What you would receive at maturity per security = A number of underlying shares of the underlying equal to the equity ratio (or, in our sole discretion, cash in an amount equal to the equity ratio × the final underlying value)

= 10 underlying shares of the underlying, with an aggregate cash value (based on the final underlying value) of $300.00

In this scenario, the underlying has depreciated from the initial underlying value to the final underlying value and the final underlying value is less than the final barrier value. As a result, you would not be repaid the stated principal amount of your securities at maturity but, instead, would receive a number of underlying shares of the underlying (or, in our sole discretion, cash based on the value thereof) worth significantly less than your initial investment.

If the final underlying value of the underlying is less than the final barrier value, we will have the option to deliver to you on the maturity date either a number of underlying shares of the underlying equal to the equity ratio or the cash value of those underlying shares based on their final underlying value. The value of those underlying shares on the maturity date may be different than their final underlying value.

Example 5—Downside Scenario B. The final underlying value is $0.00, resulting in a -100.00% underlying return. In this example, the final underlying value is less than the final barrier value.

In this scenario, the underlying shares of the underlying are worthless on the valuation date and, as a result, you would lose your entire investment in the securities at maturity.

It is possible that the final underlying value of the underlying will be less than the final barrier value, such that you will receive significantly less than the stated principal amount of your securities, and possibly nothing, at maturity.

PS-3

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 the 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.

■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 underlying. If the final underlying value is less than the final barrier value, you will not be repaid the stated principal amount of your securities at maturity but, instead, will receive underlying shares of the underlying (or, in our sole discretion, cash based on the value thereof) that will be worth significantly less than your initial investment in the securities and may be worth nothing. There is no minimum payment at maturity on the securities, and you may lose up to all of your investment.

We may elect, in our sole discretion, to pay you cash at maturity in lieu of delivering any underlying shares of the underlying. If we elect to pay you cash at maturity in lieu of delivering any underlying shares of the underlying, the amount of that cash may be less than the market value of the underlying shares on the maturity date because the market value will likely fluctuate between the valuation date and the maturity date. Conversely, if we do not exercise our cash election right and instead deliver underlying shares of the underlying to you on the maturity date, the market value of such underlying shares may be less than the cash amount you would have received if we had exercised our cash election right. We will have no obligation to take your interests into account when deciding whether to exercise our cash election right.

■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 underlying appreciates by significantly more than the digital return. If the 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 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 underlying even if the underlying appreciates by less than the digital return.

■You will not receive dividends or have any other rights with respect to the underlying unless and until you receive underlying shares of the underlying at maturity. You will not receive any dividends with respect to the underlying unless and until you receive underlying shares of the underlying at maturity. 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 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 underlying. If any change to the underlying shares of the underlying is proposed, such as an amendment to the underlying’s organizational documents, you will not have the right to vote on such change, but you will be subject to such change in the event you receive underlying shares of the underlying at maturity. Any such change may adversely affect the market value of the underlying shares of the underlying.

■Your payment at maturity depends on the closing value of the underlying on a single day. Because your payment at maturity depends on the closing value of the underlying solely on the valuation date, you are subject to the risk that the closing value of the 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 directly in the underlying or in another instrument linked to the 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 underlying, you might have achieved better returns.

■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.

PS-4

Citigroup Global Markets Holdings Inc.

■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 the closing value of the underlying, the dividend yield on the underlying 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 value of the underlying, the volatility of the closing value of the underlying, the dividend yield on the underlying, 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 value of the underlying 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 temporary upward adjustment will steadily decline to zero over the temporary adjustment period. See “Valuation of the Securities” in this pricing supplement.

■Our offering of the securities is not a recommendation of the underlying. The fact that we are offering the securities does not mean that we believe that investing in an instrument linked to the underlying 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 underlying or in instruments related to the underlying, and may publish research or express opinions, that in each case are inconsistent with an investment linked to the underlying. These and other activities of our affiliates may affect the closing value of the underlying in a way that negatively affects the value of and your return on the securities.

■The closing value of the 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 underlying or in financial instruments related to the underlying and may adjust such positions during the term of the securities. Our affiliates also take positions in the underlying or in financial instruments related to the underlying 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

PS-5

Citigroup Global Markets Holdings Inc.

affect the closing value of the underlying 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 underlying 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 the 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.

■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 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 the 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.

■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 would not.

■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. For example, if the underlying enters into a merger agreement that provides for holders of the underlying shares to receive shares of another entity and such shares are marketable securities, the closing value of the underlying following consummation of the merger will be based on the value of such other shares. Additionally, if the underlying shares 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.

■If the underlying shares are delisted, we may call the securities prior to maturity for an amount that may be less than the stated principal amount. If we exercise this call right, you will receive the amount described under “Description of the Securities—Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF—Delisting of an Underlying Company” in the accompanying product supplement. This amount may be less, and possibly significantly less, than the stated principal amount of 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. 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.

■The tax disclosure is subject to confirmation. The information set forth under “United States Federal Tax Considerations” in this pricing supplement remains subject to confirmation by our counsel following the pricing of the securities. If that information cannot be confirmed by our counsel, you may be asked to accept revisions to that information in connection with your purchase. Under these circumstances, if you decline to accept revisions to that information, your purchase of the securities will be canceled.

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Citigroup Global Markets Holdings Inc.

Information About Constellation Energy Corporation

Constellation Energy Corporation generates and distributes nuclear, hydro, wind, and solar energy solutions. The underlying shares of Constellation Energy Corporation are registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Information provided to or filed with the SEC by Constellation Energy Corporation pursuant to the Exchange Act can be located by reference to the SEC file number 001-41137 through the SEC’s website at http://www.sec.gov. In addition, information regarding Constellation Energy Corporation may be obtained from other sources including, but not limited to, press releases, newspaper articles and other publicly disseminated documents. The underlying shares of Constellation Energy Corporation trade on the NASDAQ Global Select Market under the ticker symbol “CEG.”

We have derived all information regarding Constellation Energy Corporation from publicly available information and have not independently verified any information regarding Constellation Energy Corporation. This pricing supplement relates only to the securities and not to Constellation Energy Corporation. We make no representation as to the performance of Constellation Energy Corporation over the term of the securities.

The securities represent obligations of Citigroup Global Markets Holdings Inc. (guaranteed by Citigroup Inc.) only. Constellation Energy Corporation 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 Constellation Energy Corporation on June 27, 2025 was $320.17.

The graph below shows the closing value of Constellation Energy Corporation for each day such value was available from January 19, 2022 to June 27, 2025. We obtained the closing values from Bloomberg L.P., without independent verification. If certain corporate transactions occurred during the historical period shown below, including, but not limited to, spin-offs or mergers, then the closing values shown below for the period prior to the occurrence of any such transaction have been adjusted by Bloomberg L.P. as if any such transaction had occurred prior to the first day in the period shown below. You should not take historical closing values as an indication of future performance.

Constellation Energy Corporation – Historical Closing Values January 19, 2022 to June 27, 2025

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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. This discussion does not address the U.S. federal tax consequences of the ownership or disposition of the underlying shares that you may receive at maturity. You should consult your tax adviser regarding the U.S. federal tax consequences of the ownership and disposition of the underlying shares.

We expect that our counsel will advise us that, based on current market conditions, a security should 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. The information set forth under this section remains subject to confirmation by our counsel following the pricing of the securities. If that information cannot be confirmed by our counsel, you may be asked to accept revisions to that information in connection with your purchase. Under these circumstances, if you decline to accept revisions to that information, your purchase of the securities will be canceled.

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 for cash), you should recognize capital gain or loss equal to the difference between the amount realized and your tax basis in the security. Such gain or loss should be long-term capital gain or loss if you held the security for more than one year.

●If you receive the underlying shares (and cash in lieu of any fractional shares) at maturity, you should not recognize gain or loss with respect to the underlying shares received. Instead, you should have an aggregate tax basis in the underlying shares received (including any fractional shares deemed received) equal to your basis in the securities. Your holding period for any underlying shares received should start on the day after receipt. With respect to any cash received in lieu of a fractional share, you should recognize capital loss in an amount equal to the difference between the amount of cash received in lieu of the fractional share and the portion of your tax basis in the securities that is allocable to the fractional share.

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 market conditions as of the date of this preliminary pricing supplement, we expect that the securities will 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.

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.

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 $11.00 for each security sold in this offering. The actual underwriting fee will be equal to the selling concession and

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Citigroup Global Markets Holdings Inc.

structuring fee provided to selected dealers, as described in this paragraph. From this underwriting fee, CGMI will pay selected dealers not affiliated with CGMI a selling concession of $10.00 for each security they sell and a structuring fee of up to $1.00 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.”

Certain Selling Restrictions

Cayman Islands

Pursuant to the Companies Law (as amended) of the Cayman Islands, no invitation may be made to the public in the Cayman Islands to subscribe for the securities by or on behalf of the issuer unless at the time of such invitation the issuer is listed on the Cayman Islands Stock Exchange. The issuer is not presently listed on the Cayman Islands Stock Exchange and, accordingly, no invitation to the public in the Cayman Islands is to be made by the issuer (or by any dealer on its behalf). No such invitation is made to the public in the Cayman Islands hereby.

British Virgin Islands

This offering shall not constitute an offer, invitation or solicitation to any member of the public in the British Virgin Islands for purposes of the Securities and Investment Business Act, 2010, of the British Virgin Islands.

Israel

No prospectus in relation to the securities has been, or will be, issued in Israel and/or reviewed by the Israel Securities Authority. Each underwriter has represented, warranted and agreed, and each further underwriter will be required to represent, warrant and agree, that it will not offer or sell securities in the State of Israel other than private sales to Israeli persons who are investors of the type listed in the First Supplement to the Securities Law, 5728-1968 and who have confirmed to the underwriter in writing that (i) they are an investor of the type listed in the First Supplement to the Securities Law, 5728-1968, of the State of Israel, and that they are aware of the significance of their being such an investor and consent thereto, and (ii) they are purchasing the securities for their own account, for investment purposes only and with no present intention of distribution or re-sale.

Switzerland

Each underwriter has represented, warranted and agreed, and each further underwriter will be required to represent, warrant and agree, that it has not offered and will not offer, directly or indirectly, securities to the public in Switzerland, and have not distributed or caused to be distributed and will not distribute or cause to be distributed to the public in Switzerland, this pricing supplement and the accompanying product supplement, prospectus supplement and prospectus or any other offering material relating to the securities, other than pursuant to an exemption under article 36(1) of the Swiss Federal Financial Services Act (“FinSA”) or where such offer or distribution does not qualify as a public offer in Switzerland, provided that no such offer of securities shall require the issuer or any agent to publish a prospectus pursuant to FinSA. For these purposes “public offer” refers to the respective definitions in article 3(g) and (h) of FinSA and as further detailed in the implementing Swiss Federal Financial Services Ordinance (“FinSO”).

No key information document under article 58 of FinSA or article 59(2) of FinSA in respect of the securities has been prepared and published. Accordingly, the securities may not be offered to private clients within the meaning of FinSA in Switzerland. For these purposes, a private client means a person who is not one (or more) of the following: (i) a professional client as defined in article 4(3) of FinSA (not having opted-in on the basis of article 5(5) of FinSA) or article 5(1) of FinSA; or (ii) an institutional client as defined in article 4(4) of FinSA; or (iii) a private client with an asset management agreement according to article 58(2) of FinSA. For these purposes “offer” refers to the interpretation of such term in article 58 of FinSA.

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Citigroup Global Markets Holdings Inc.

This pricing supplement is not intended to constitute an advertising document within the meaning of article 68 of FinSA and article 95 of FinSO.

The securities do not constitute a participation in a collective investment scheme in the meaning of the Swiss Federal Act on Collective Investment Schemes and are not licensed by the Swiss Financial Market Supervisory Authority (“FINMA”) thereunder. Accordingly, neither the securities nor holders of the securities benefit from protection under the Swiss Federal Act on Collective Investment Schemes or supervision by the Swiss FINMA and investors are exposed to the credit risk of the issuer and guarantor (if applicable).

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.

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FAQ

What is the Upside Gearing on JPMorgan’s Trigger GEARS linked to the EURO STOXX 50?

The notes provide 1.93× leveraged exposure to any positive index return at maturity.

How much downside protection do the Trigger GEARS offer?

Principal is protected only if the final index level remains at or above 75 % of the initial 5,244.03 level (3,933.02). Below that, losses are 1-for-1.

Do the securities pay interest or dividends?

No. The notes pay no coupons and pass through none of the dividends paid by EURO STOXX 50 constituents.

What fees are associated with this 424B2 offering?

UBS receives a $0.35 selling commission per $10 note (3.5 %); net proceeds to the issuer are $9.65.

What is the estimated value versus the public offering price?

JPMorgan calculates an estimated value of $9.561 per $10 note, about 4.4 % below the $10 issue price.

When do the Trigger GEARS mature?

The securities mature on 28 June 2030, with the final valuation date set for 26 June 2030.