[424B2] Citigroup Inc. Prospectus Supplement

Rhea-AI Filing Summary

Citigroup Global Markets Holdings Inc. (guaranteed by Citigroup Inc.) is offering Autocallable Contingent-Coupon Equity-Linked Securities tied to the iShares® MSCI Brazil ETF (EWZ). The notes are unsecured senior obligations with a scheduled maturity of 22 January 2027, but may be redeemed automatically as early as the first potential autocall date on 20 January 2026 if EWZ closes at or above its initial level.

Income potential. Investors receive a contingent coupon of at least 2.3375 % per quarter (≥ 9.35 % p.a.) on each payment date only when EWZ’s closing value on the preceding valuation date is ≥ 70 % of the initial level (the coupon-barrier). Missed coupons are not made up. Early redemption, when triggered, returns the full principal plus the due coupon, capping further income.

Downside exposure. If the notes are not called and EWZ closes below 70 % of the initial level on the final valuation date, investors receive a fixed number of EWZ shares (or cash equivalent) worth less than the $1,000 principal—and potentially zero—resulting in up to a 100 % loss. There is no upside participation above par.

Key structural terms.

• Stated principal: $1,000 per note
• Coupon & final barriers: 70 % of initial EWZ level
• Valuation dates: 6 (quarterly) with 4 that also serve as potential autocall dates
• Issue price: $1,000 (fee-based accounts $975–$980); underwriting fee up to $25 (2.50 %)
• Estimated value on pricing date: ≥ $913.50 (c. 91 % of issue price)
• No exchange listing; liquidity solely via dealer bid
• All payments subject to Citigroup and Citi Inc. credit risk

Investor considerations. The product targets yield-seeking investors comfortable with emerging-market equity volatility, potential illiquidity and full principal-at-risk structures. The 70 % barrier offers moderate protection, but significant downside risk remains, especially given Brazil-specific and currency risks inherent in EWZ.

Insights

Structured Products Analyst

TL;DR High coupon compensates for sizable Brazil ETF risk; principal is not protected and early call caps upside.

The note provides an above-market coupon floor (≥ 9.35 % p.a.) contingent on EWZ staying at or above 70 % of its start level. The 30 % downside buffer is typical for emerging-market linked deals but thin in volatile regimes—EWZ has historically moved ±40-60 % in 12-month windows. Early-call mechanics mean favourable EWZ performance results in par return only, limiting effective yield to roughly four or five coupons if autocall occurs at the first opportunity. Pricing shows a 8-9 % discount to issue, reflecting fees and hedging. Given Citi’s investment-grade profile, credit risk is acceptable, but investors must tolerate mark-to-market swings and potential illiquidity. Overall risk/return appears balanced but uncompelling versus alternative income strategies.

Risk Analyst

TL;DR Note embeds multiple layers of risk: emerging-market equity, currency, credit, and liquidity.

Principal risk is binary: a single close below the 70 % barrier on the final date converts repayment into EWZ shares, exposing holders to emerging-market turmoil, FX devaluation and potential settlement friction. Coupon non-payment probability rises sharply as volatility or currency weakness increases. The unlisted status means secondary bids will likely sit well below theoretical value, particularly amid Brazilian market stress. Credit spread widening for Citi could further pressure valuations. Investors are paid a modest premium (≈400 bp over senior Citi debt) for these risks—arguably thin. I classify overall impact as neutral, leaning negative for conservative portfolios.

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 JULY 10, 2025

Citigroup Global Markets Holdings Inc.

July     , 2025 Medium-Term Senior Notes, Series N Pricing Supplement No. 2025-USNCH27545 Filed Pursuant to Rule 424(b)(2) Registration Statement Nos. 333-270327 and 333-270327-01

Autocallable Contingent Coupon Equity Linked Securities Linked to the iShares^® MSCI Brazil ETF Due January 22, 2027

▪The securities offered by this pricing supplement are unsecured debt securities issued by Citigroup Global Markets Holdings Inc. and guaranteed by Citigroup Inc. The securities offer the potential for periodic contingent coupon payments at an annualized rate that, if all are paid, would produce a yield that is generally higher than the yield on our conventional debt securities of the same maturity. In exchange for this higher potential yield, you must be willing to accept the risks that (i) your actual yield may be lower than the yield on our conventional debt securities of the same maturity because you may not receive one or more, or any, contingent coupon payments, (ii) the value of what you receive at maturity may be significantly less than the stated principal amount of your securities, and may be zero, and (iii) the securities may be automatically called for redemption prior to maturity beginning on the first potential autocall date specified below. Each of these risks will depend on the performance of the underlying specified below. Although you will have downside exposure to the underlying, you will not receive dividends with respect to the underlying or participate in any appreciation of the underlying.

▪Investors in the securities must be willing to accept (i) an investment that may have limited or no liquidity and (ii) the risk of not receiving any payments 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:	The iShares® MSCI Brazil ETF
Stated principal amount:	$1,000 per security
Pricing date:	July 18, 2025
Issue date:	July 23, 2025
Valuation dates:	October 20, 2025, January 20, 2026, April 20, 2026, July 20, 2026, October 19, 2026 and January 19, 2027 (the “final valuation date”), each subject to postponement if such date is not a scheduled trading day or certain market disruption events occur
Maturity date:	Unless earlier redeemed, January 22, 2027
Contingent coupon payment dates:	The third business day after each valuation date, except that the contingent coupon payment date following the final valuation date will be the maturity date
Contingent coupon:	On each contingent coupon payment date, unless previously redeemed, the securities will pay a contingent coupon equal to at least 2.3375% of the stated principal amount of the securities (equivalent to a contingent coupon rate of at least 9.35% per annum) (to be determined on the pricing date) if and only if the closing value of the underlying on the immediately preceding valuation date is greater than or equal to the coupon barrier value. If the closing value of the underlying on any valuation date is less than the coupon barrier value, you will not receive any contingent coupon payment on the immediately following contingent coupon payment date.
Payment at maturity:	If the securities are not automatically redeemed prior to maturity, you will receive at maturity for each security you then hold (in addition to the final contingent coupon payment, if applicable): ■If the final underlying value is greater than or equal to the final barrier value: $1,000 ■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 securities are not automatically redeemed prior to maturity and 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, and you will not receive any contingent coupon payment 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 final valuation date
Coupon barrier value:	$, 70.00% of the initial underlying value
Final barrier value:	$, 70.00% of the initial underlying value
Equity ratio:	, the stated principal amount divided by the initial underlying value
Listing:	The securities will not be listed on any securities exchange
Underwriter:	Citigroup Global Markets Inc. (“CGMI”), an affiliate of the issuer, acting as principal
Underwriting fee and issue price:	Issue price(1)(2)	Underwriting fee(3)	Proceeds to issuer(4)
Per security:	$1,000.00	$25.00	$975.00
Total:	$	$	$

(Key Terms continued on next page)

(1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least $913.50 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) The issue price for investors purchasing the securities in fee-based advisory accounts will be $975.00 per security, assuming no custodial fee is charged by a selected dealer, and up to $980.00 per security, assuming the maximum custodial fee is charged by a selected dealer. See “Supplemental Plan of Distribution” in this pricing supplement.

(3) CGMI will receive an underwriting fee of up to $25.00 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.

(4) 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-6.

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-04-10 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.

KEY TERMS (continued)
Automatic early redemption:	If, on any potential autocall date, the closing value of the underlying is greater than or equal to  the initial underlying value, each security you then hold will be automatically called on that potential autocall date for redemption on the immediately following contingent coupon payment date for an amount in cash equal to $1,000 plus the related contingent coupon payment. The automatic early redemption feature may significantly limit your potential return on the securities. If the underlying performs in a way that would otherwise be favorable, the securities are likely to be automatically called for redemption prior to maturity, cutting short your opportunity to receive contingent coupon payments. The securities may be automatically called for redemption as early as the first potential autocall date specified below.
Potential autocall dates:	The valuation dates scheduled to occur on January 20, 2026, April 20, 2026, July 20, 2026 and October 19, 2026
CUSIP / ISIN:	17333H6S8 / US17333H6S87

PS-2

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 that are traded on a U.S. national securities exchange. Please see the accompanying product supplement for more information.

Underlying Prospectus. In addition to this pricing supplement and the accompanying product supplement, prospectus supplement and prospectus, you should read the prospectus for the underlying on file at the SEC website, which can be accessed via the hyperlink below. The contents of that prospectus and any documents incorporated by reference therein are not incorporated by reference herein or in any way made a part hereof.

Prospectus for iShares^® MSCI Brazil ETF dated February 28, 2025:

https://www.sec.gov/Archives/edgar/data/930667/000119312525033724/d890529dex99a66.htm

PS-3

Citigroup Global Markets Holdings Inc.

Hypothetical Examples

The examples in the first section below illustrate how to determine whether a contingent coupon will be paid and whether the securities will be automatically called for redemption following a valuation date that is also a potential autocall date. The examples in the second section below illustrate how to determine the payment at maturity on the securities, assuming the securities are not automatically redeemed prior to maturity. The examples are solely for illustrative purposes, do not show all possible outcomes and are not a prediction of any payment that may be made on the securities.

The examples below are based on the following hypothetical values and do not reflect the actual initial underlying value, coupon barrier value, final barrier value or equity ratio. For the actual initial underlying value, coupon barrier 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 the actual payments on the securities will be calculated based on the actual initial underlying value, coupon barrier value, final barrier value and equity ratio, and not the hypothetical values indicated below. For ease of analysis, figures below have been rounded. The examples below assume that the contingent coupon rate is set at the lowest value indicated on the cover page of this pricing supplement. The actual contingent coupon rate will be determined on the pricing date.

Hypothetical initial underlying value:	$100.00
Hypothetical coupon barrier value:	$70.00 (70.00% of the hypothetical initial underlying value)
Hypothetical final barrier value:	$70.00 (70.00% of the hypothetical initial underlying value)
Hypothetical equity ratio:	10.00000 (the stated principal amount divided by the hypothetical initial underlying value)

Hypothetical Examples of Contingent Coupon Payments and any Payment upon Automatic Early Redemption Following a Valuation Date that is also a Potential Autocall Date

The three hypothetical examples below illustrate how to determine whether a contingent coupon will be paid and whether the securities will be automatically redeemed following a hypothetical valuation date that is also a potential autocall date, assuming that the closing value of the underlying on the hypothetical valuation date is as indicated below.

	Hypothetical closing value of the underlying on hypothetical valuation date	Hypothetical payment per $1,000.00 security on related contingent coupon payment date
Example 1	$85 (greater than coupon barrier value; less than initial underlying value)	$23.375 (contingent coupon is paid; securities not redeemed)
Example 2	$45 (less than coupon barrier value)	$0.00 (no contingent coupon; securities not redeemed)
Example 3	$110 (greater than coupon barrier value and initial underlying value)	$1,023.375 (contingent coupon is paid; securities redeemed)

Example 1: On the hypothetical valuation date, the closing value of the underlying is greater than the coupon barrier value but less than the initial underlying value. As a result, investors in the securities would receive the contingent coupon payment on the related contingent coupon payment date and the securities would not be automatically redeemed.

Example 2: On the hypothetical valuation date, the closing value of the underlying is less than the coupon barrier value. As a result, investors would not receive any payment on the related contingent coupon payment date and the securities would not be automatically redeemed.

Investors in the securities will not receive a contingent coupon on the contingent coupon payment date following a valuation date if the closing value of the underlying on that valuation date is less than the coupon barrier value.

Example 3: On the hypothetical valuation date, the closing value of the underlying is greater than both the coupon barrier value and the initial underlying value. As a result, the securities would be automatically redeemed on the related contingent coupon payment date for an amount in cash equal to $1,000.00 plus the related contingent coupon payment.

If the hypothetical valuation date were not also a potential autocall date, the securities would not be automatically redeemed on the related contingent coupon payment date.

PS-4

Citigroup Global Markets Holdings Inc.

Hypothetical Examples of the Payment at Maturity on the Securities

The next three hypothetical examples illustrate the calculation of the payment at maturity on the securities, assuming that the securities have not been earlier automatically redeemed and that the final underlying value is as indicated below.

	Hypothetical final underlying value	Hypothetical payment at maturity per $1,000.00 security
Example 4	$110 (greater than final barrier value)	$1,023.375 (contingent coupon is paid)
Example 5	$30 (less than final barrier value)	A number of underlying shares of the underlying (or, in our sole discretion, cash) worth $300.00 based on the final underlying value
Example 6	$20 (less than final barrier value)	A number of underlying shares of the underlying (or, in our sole discretion, cash) worth $200.00 based on the final underlying value

Example 4: The final underlying value is greater than the final barrier value. Accordingly, at maturity, you would receive the stated principal amount of the securities plus the contingent coupon payment due at maturity, but you would not participate in the appreciation of the underlying.

Example 5: The final underlying value is less than the final barrier value. Accordingly, at maturity, you would receive for each security you then hold a fixed number of underlying shares of the underlying equal to the equity ratio (or, at our option, the cash value thereof).

In this scenario, the value of a number of underlying shares of the underlying equal to the equity ratio, based on the final underlying value, would be $300.00. Therefore, the value of the underlying shares of the underlying (or, in our discretion, cash) you receive at maturity would be significantly less than the stated principal amount of your securities. You would incur a loss based on the performance of the underlying from the initial underlying value to the final underlying value. In addition, because the final underlying value is below the coupon barrier value, you would not receive any contingent coupon payment at maturity.

If the final underlying value 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 6: The final underlying value is less than the final barrier value. Accordingly, at maturity, you would receive for each security you then hold a fixed number of underlying shares of the underlying equal to the equity ratio (or, at our option, the cash value thereof).

In this scenario, the value of a number of underlying shares of the underlying equal to the equity ratio, based on the final underlying value, would be $200.00. Therefore, the value of the underlying shares of the underlying (or, in our discretion, cash) you receive at maturity would be significantly less than the stated principal amount of your securities. You would incur a loss based on the performance of the underlying from the initial underlying value to the final underlying value. In addition, because the final underlying value is less than the coupon barrier value, you would not receive any contingent coupon payment at maturity.

If the final underlying value 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.

It is possible that the closing value of the underlying will be less than the coupon barrier value on each valuation date and less than the final barrier value on the final valuation date, such that you will not receive any contingent coupon payments over the term of the securities and will receive significantly less than the stated principal amount of your securities, and possibly nothing, at maturity.

PS-5

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.

Citigroup Inc. will release quarterly earnings on July 15, 2025, which is during the marketing period and prior to the pricing date of these securities.

■You may lose a significant portion or all of your investment. Unlike conventional debt securities, the securities do not provide for the repayment of the stated principal amount at maturity in all circumstances. If the securities are not automatically redeemed prior to maturity and the final underlying value is less than the final barrier value, you will not receive 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 the stated principal amount and possibly 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. If we elect to pay you cash at maturity in lieu of delivering any underlying shares, 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 final valuation date and the maturity date. Conversely, if we do not exercise our cash election right and instead deliver underlying shares 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.

■You will not receive any contingent coupon on the contingent coupon payment date following any valuation date on which the closing value of the underlying is less than the coupon barrier value. A contingent coupon payment will be made on a contingent coupon payment date if and only if the closing value of the underlying on the immediately preceding valuation date is greater than or equal to the coupon barrier value. If the closing value of the underlying on any valuation date is less than the coupon barrier value, you will not receive any contingent coupon payment on the immediately following contingent coupon payment date. If the closing value of the underlying on each valuation date is below the coupon barrier value, you will not receive any contingent coupon payments over the term of the securities.

■Higher contingent coupon rates are associated with greater risk. The securities offer contingent coupon payments at an annualized rate that, if all are paid, would produce a yield that is generally higher than the yield on our conventional debt securities of the same maturity. This higher potential yield is associated with greater levels of expected risk as of the pricing date for the securities, including the risk that you may not receive a contingent coupon payment on one or more, or any, contingent coupon payment dates and the risk that the value of what you receive at maturity may be significantly less than the stated principal amount of your securities and may be zero. The volatility of the closing value of the underlying is an important factor affecting these risks. Greater expected volatility of the closing value of the underlying as of the pricing date may result in a higher contingent coupon rate, but would also represent a greater expected likelihood as of the pricing date that the closing value of the underlying on one or more valuation dates will be less than the coupon barrier value, such that you will not receive one or more, or any, contingent coupon payments during the term of the securities and that the final underlying value will be less than the final barrier value, such that you will not be repaid the stated principal amount of your securities at maturity.

■You may not be adequately compensated for assuming the downside risk of the underlying. The potential contingent coupon payments on the securities are the compensation you receive for assuming the downside risk of the underlying, as well as all the other risks of the securities. That compensation is effectively “at risk” and may, therefore, be less than you currently anticipate. First, the actual yield you realize on the securities could be lower than you anticipate because the coupon is “contingent” and you may not receive a contingent coupon payment on one or more, or any, of the contingent coupon payment dates. Second, the contingent coupon payments are the compensation you receive not only for the downside risk of the underlying, but also for all of the other risks of the securities, including the risk that the securities may be automatically redeemed prior to maturity, interest rate risk and our and Citigroup Inc.’s credit risk. If those other risks increase or are otherwise greater than you currently anticipate, the contingent coupon payments may turn out to be inadequate to compensate you for all the risks of the securities, including the downside risk of the underlying.

■The securities may be automatically redeemed prior to maturity, limiting your opportunity to receive contingent coupon payments. On any potential autocall date, the securities will be automatically called for redemption if the closing value of the underlying on that potential autocall date is greater than or equal to the initial underlying value. As a result, if the underlying performs in a way that would otherwise be favorable, the securities are likely to be automatically redeemed, cutting short your opportunity to receive contingent coupon payments. If the securities are automatically redeemed prior to maturity, you may not be able to reinvest your funds in another investment that provides a similar yield with a similar level of risk.

■The securities offer downside exposure to the underlying, but no upside exposure to the underlying. You will not participate in any appreciation in the value of the underlying over the term of the securities. Consequently, your return on the securities will be limited to

PS-6

Citigroup Global Markets Holdings Inc.

the contingent coupon payments you receive, if any, and may be significantly less than the return on the underlying over the term of the securities. In addition, as an investor in the securities, you will not receive any dividends or other distributions or have any other rights with respect to the underlying.

■The performance of the securities will depend on the closing value of the underlying solely on the valuation dates, which makes the securities particularly sensitive to volatility in the closing value of the underlying on or near the valuation dates. Whether the contingent coupon will be paid on any given contingent coupon payment date and whether the securities will be automatically redeemed prior to maturity will depend on the closing value of the underlying solely on the applicable valuation dates, regardless of the closing value of the underlying on other days during the term of the securities. If the securities are not automatically redeemed prior to maturity, what you receive at maturity will depend solely on the closing value of the underlying on the final valuation date, and not on any other day during the term of the securities. Because the performance of the securities depends on the closing value of the underlying on a limited number of dates, the securities will be particularly sensitive to volatility in the closing value of the underlying on or near the valuation dates. You should understand that the closing value of the underlying has historically been highly volatile.

■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 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

PS-7

Citigroup Global Markets Holdings Inc.

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.

■The underlying is subject to risks associated with emerging markets. The stocks included in the underlying have been issued by companies in various foreign emerging markets. Foreign equity securities involve risks associated with the securities markets in foreign countries, including risks of volatility in those markets, governmental intervention in those markets and cross-shareholdings in companies in certain countries. There is also generally less publicly available information about foreign companies than about U.S. companies that are subject to the reporting requirements of the Securities and Exchange Commission, and foreign companies are subject to accounting, auditing and financial reporting standards and requirements different from those applicable to U.S. reporting companies. The prices of securities in foreign markets may be affected by political, economic, financial and social factors in those countries, or global regions, including changes in government, economic and fiscal policies and currency exchange laws. Stocks issued by companies in emerging markets may be subject to heightened risks, including risks of relatively unstable governments, nationalization of businesses, restrictions on foreign ownership, prohibitions on the repatriation of assets and less protection of property rights. The economies of countries with emerging markets may be based on only a few industries, be highly vulnerable to changes in local or global trade conditions and suffer from extreme and volatile debt burdens or inflation rates. Local securities markets may trade a small number of securities and be unable to respond effectively to increases in trading volume, potentially increasing price volatility. Moreover, the economies in such countries may differ unfavorably from the economy in the United States in such respects as growth of gross national product, rate of inflation, capital reinvestment, resources and self-sufficiency.

■Fluctuations in exchange rates will affect the closing value of the iShares^® MSCI Brazil ETF. Because the iShares^® MSCI Brazil ETF includes stocks that trade outside the United States and the closing value of the iShares^® MSCI Brazil ETF is based on the U.S. dollar value of those stocks, the iShares^® MSCI Brazil ETF is subject to currency exchange rate risk with respect to each of the currencies in which such stocks trade. Exchange rate movements may be volatile and may be driven by numerous factors specific to the relevant countries, including the supply of, and the demand for, the applicable currencies, as well as government policy and intervention and macroeconomic factors. Exchange rate movements may also be influenced significantly by speculative trading. In general, if the U.S. dollar strengthens against the currencies in which the stocks included in the iShares^® MSCI Brazil ETF trade, the closing value of the iShares^® MSCI Brazil ETF will be adversely affected for that reason alone.

■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 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.

PS-8

Citigroup Global Markets Holdings Inc.

■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.

■The value and performance of the underlying shares 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. 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 underlying may affect the value of your securities. The sponsor of the underlying may at any time make methodological changes or other changes in the manner in which it operates that could affect the value of the underlying. We are not affiliated with the underlying sponsor and, accordingly, we have no control over any changes such sponsor may make. Such changes could adversely affect the performance of the underlying 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 described in “United States Federal Tax Considerations” below. 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.

Non-U.S. investors should note that persons having withholding responsibility in respect of the securities may withhold on any coupon payment paid to a non-U.S. investor, generally at a rate of 30%. To the extent that we have withholding responsibility in respect of the securities, we intend to so withhold.

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-9

Citigroup Global Markets Holdings Inc.

Information About the iShares^® MSCI Brazil ETF

The iShares^® MSCI Brazil ETF is an exchange-traded fund that seeks to provide investment results that correspond generally to the price and yield performance, before fees and expenses, of an index composed of Brazilian equities, which is currently the MSCI Brazil 25/50 Index. The MSCI Brazil 25/50 Index was developed by MSCI Inc. as an equity benchmark for Brazilian stock performance, and is designed to measure equity market performance of the large- and mid-cap segments of the Brazilian equity market.

The iShares^® MSCI Brazil ETF is an investment portfolio managed by iShares^® Inc. BlackRock Fund Advisors is the investment adviser to the iShares^® MSCI Brazil ETF. iShares^® , Inc. is a registered investment company that consists of numerous separate investment portfolios, including the iShares® MSCI Brazil ETF.

Information provided to or filed with the SEC by iShares^®, Inc. 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 033-97598 and 811-09102, 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 iShares^® MSCI Brazil ETF trade on the NYSE Arca under the ticker symbol “EWZ.”

You may receive underlying shares of the iShares^® MSCI Brazil ETF at maturity. Therefore, in making your decision to invest in the securities, you should review the prospectus related to the iShares^® MSCI Brazil ETF on file at the SEC, which can be accessed via the hyperlink below.

Prospectus effective on or around February 28, 2025: https://www.sec.gov/Archives/edgar/data/930667/000119312525033724/d890529dex99a66.htm

The contents of that prospectus and any documents incorporated by reference therein are not incorporated by reference herein or in any way made a part hereof.

We have derived all information regarding the iShares^® MSCI Brazil ETF from publicly available information and have not independently verified any information regarding the iShares^® MSCI Brazil ETF. This pricing supplement relates only to the securities and not to the iShares^® MSCI Brazil ETF. We make no representation as to the performance of the iShares^® MSCI Brazil ETF 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 iShares^® MSCI Brazil ETF 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 iShares^® MSCI Brazil ETF on July 9, 2025 was $28.16.

The graph below shows the closing value of the iShares^® MSCI Brazil ETF for each day such value was available from January 2, 2015 to July 9, 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.

iShares^® MSCI Brazil ETF – Historical Closing Values January 2, 2015 to July 9, 2025

PS-10

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.

Due to the lack of any controlling legal authority, there is substantial uncertainty regarding the U.S. federal tax consequences of an investment in the securities. In connection with any information reporting requirements we may have in respect of the securities under applicable law, we intend (in the absence of an administrative determination or judicial ruling to the contrary) to treat the securities for U.S. federal income tax purposes as prepaid forward contracts with associated coupon payments that will be treated as gross income to you at the time received or accrued in accordance with your regular method of tax accounting. In the opinion of our counsel, Davis Polk & Wardwell LLP, this treatment of the securities is reasonable under current law; however, our counsel has advised us that it is unable to conclude affirmatively that this treatment is more likely than not to be upheld, and that alternative treatments are possible. 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:

●Any coupon payments on the securities should be taxable as ordinary income to you at the time received or accrued in accordance with your regular method of accounting for U.S. federal income tax purposes.

●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. For this purpose, the amount realized does not include any coupon paid on retirement and may not include sale proceeds attributable to an accrued coupon, which may be treated as a coupon payment. Such gain or loss should be long-term capital gain or loss if you held the security for more than one year.

●If, upon retirement of the securities, you receive underlying shares, you should not recognize gain or loss with respect to the underlying shares received, other than any fractional underlying share for which you receive cash. Your basis in any underlying shares received, including any fractional underlying share deemed received, should be equal to your tax 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.

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 particular U.S. federal tax consequences of the ownership and disposition of the underlying shares.

Withholding Tax on Non-U.S. Holders. Because significant aspects of the tax treatment of the securities are uncertain, persons having withholding responsibility in respect of the securities may withhold on any coupon payment paid to Non-U.S. Holders (as defined in the accompanying product supplement), generally at a rate of 30%. To the extent that we have (or an affiliate of ours has) withholding responsibility in respect of the securities, we intend to so withhold. In order to claim an exemption from, or a reduction in, the 30% withholding, you may need to comply with certification requirements to establish that you are not a U.S. person and are eligible for such an exemption or reduction under an applicable tax treaty. You should consult your tax adviser regarding the tax treatment of the securities, including the possibility of obtaining a refund of any amounts withheld and the certification requirement described above.

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.

We will not be required to pay any additional amounts with respect to amounts withheld.

PS-11

Citigroup Global Markets Holdings Inc.

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.

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 $25.00 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, plus $5.00 per security in the case of securities sold to fee-based advisory accounts. From this underwriting fee, CGMI will pay selected dealers not affiliated with CGMI a variable selling concession of up to $25.00 for each security they sell to accounts other than fee-based advisory accounts. CGMI will pay selected dealers not affiliated with CGMI, which may include dealers acting as custodians, a variable selling concession of up to $5.00 for each security they sell to fee-based advisory accounts. For the avoidance of doubt, any fees or selling concessions described in this pricing supplement will not be rebated if the securities are automatically redeemed prior to maturity.

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 certain terms of the securities have not yet been fixed and 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-12

FAQ

What is the coupon rate on Citigroup’s EWZ-linked autocallable notes (symbol C)?

The notes pay a contingent coupon of at least 2.3375 % per quarter, equal to ≥ 9.35 % per annum, when conditions are met.

When can the Citigroup EWZ notes be automatically redeemed?

They are called if EWZ’s closing value on any potential autocall date (20 Jan 26, 20 Apr 26, 20 Jul 26, 19 Oct 26) is ≥ the initial level.

How much principal protection do the notes offer?

None. If EWZ closes below 70 % of its initial value on the final valuation date, holders receive EWZ shares (or cash) worth less than—and possibly zero of—the $1,000 principal.

Are the notes listed on an exchange?

No. They are unlisted; liquidity depends on Citigroup Global Markets Inc.’s secondary bids, which may be limited.

What is the estimated value versus the issue price?

Citigroup estimates the fair value on the pricing date at ≈ $913.50 per $1,000 note, about 8-9 % below the issue price.

Do investors participate in EWZ upside beyond par?

No. Returns are limited to the contingent coupons and $1,000 principal if called or if the final value is above the barrier.