[424B2] Citigroup Inc. Prospectus Supplement

Rhea-AI Filing Summary

Citigroup Global Markets Holdings Inc., fully and unconditionally guaranteed by Citigroup Inc., is offering Market-Linked Senior Notes tied to the performance of NVIDIA Corporation common stock. These unsecured notes carry no coupon and mature on September 23, 2026 (issue date: July 23, 2025; pricing date: July 18, 2025). The stated principal amount is $1,000 per note.

Upside: If NVIDIA’s ending value exceeds its starting value, holders receive the principal plus 150 % participation in the appreciation, capped at a minimum 28 % maximum return (≥ $1,280 total payout).

Downside: A 15 % buffer applies. If NVIDIA falls ≤ 15 %, principal is repaid in full. If it falls by more than 15 %, investors lose principal on a 1-for-1 basis beyond the buffer—potentially up to 85 % loss.

Key structural features include: no periodic interest or dividends, secondary-market liquidity likely limited (no exchange listing), and all payments subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc. The expected initial estimated value is at least $912.00, below the $1,000 offering price, reflecting dealer spreads and hedging costs.

Underwriting: Citigroup Global Markets Inc. acts as lead agent; Wells Fargo Securities distributes the notes. Maximum underwriting discount/commission is 2.575 % ($25.75 per note), leaving net proceeds of roughly $974.25 per note to the issuer.

Positive

• 150% participation offers leveraged exposure to NVIDIA’s upside.
• 15% downside buffer protects principal against moderate declines.
• Citigroup Inc. guarantee adds credit support compared with non-guaranteed issuers.

Negative

• Investors may lose up to 85% of principal if NVIDIA drops more than 15%.
• Upside is capped at ~28%, limiting return potential relative to direct stock ownership.
• Estimated value ($912) is materially below issue price, reflecting high embedded costs.
• Product is not exchange-listed, creating potential liquidity constraints.
• Payments are subject to Citigroup credit risk; a default would impair recoveries.

Insights

Structured-Products Analyst

TL;DR: Routine structured note, modest upside (28%) with 150% leverage, 15% buffer; principal at risk, minor impact on Citigroup.

The offering is a standard market-linked note from Citi’s long-running Series N MTN program. Terms are typical: 150% leveraged upside, a 28% cap (to be fixed on pricing), and a 15% downside buffer. These structures cater to retail investors seeking amplified equity exposure with partial protection.
From Citi’s perspective the issuance is immaterial to consolidated financials; note proceeds are largely hedged via equity derivatives. Credit exposure for investors rests on Citi and its holding-company guarantee. For NVIDIA, the product has no direct impact. Overall, the filing discloses all risks clearly, but adds no new strategic or financial insight on Citigroup; therefore impact on C equity valuation is negligible.

Risk Analyst

TL;DR: Investors face credit risk, 85% loss potential, illiquidity; ordinary issuance, not material to Citi’s risk profile.

The note embeds three core risks: (1) market risk on NVIDIA shares, partially mitigated by a 15% buffer but limited upside via a 28% cap; (2) credit risk—payments rely on Citigroup entities, although Citi’s senior unsecured rating remains investment-grade; (3) liquidity risk due to lack of listing.
Because the instrument is fully hedged, Citi’s residual risk is spread/fee income after derivative costs, so balance-sheet impact is trivial. For note buyers, effective value is $912 vs. $1,000 purchase price, indicating a sizable implied fee. Overall disclosure is adequate; risk-return trade-off skews unfavorably once fees are considered.

The information in this preliminary pricing supplement is not complete and may be changed. 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 27, 2025

Filed Pursuant to Rule 424(b)(2)

Registration Statement Nos. 333-270327 and 333-270327-01

July       , 2025 Medium-Term Senior Notes, Series N Pricing Supplement No. 2025-USNCH27365 to Product Supplement No. EA-08-02
dated March 23, 2023 and Prospectus Supplement and Prospectus each dated March 7, 2023  

Citigroup Global Markets Holdings Inc.

All Payments Due from Citigroup Global Markets Holdings Inc. Fully and Unconditionally Guaranteed by Citigroup Inc.

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside

Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

n Linked to NVIDIA Corporation (the “underlying”)

n Unlike ordinary debt securities, the securities do not pay interest or repay a fixed amount of principal at maturity. Instead, the securities provide for a maturity payment amount that may be greater than, equal to or less than the stated principal amount of the securities, depending on the performance of the underlying from the starting value to the ending value, subject to the maximum return. The maturity payment amount will reflect the following terms:

n If the value of the underlying increases, you will receive the stated principal amount plus a positive return equal to 150% of the percentage increase in the value of the underlying from the starting value, subject to a maximum return of at least 28.00% (to be determined on the pricing date) of the stated principal amount

n If the value of the underlying decreases, but the decrease is not more than 15% (the “buffer amount”), you will be repaid the stated principal amount

n If the value of the underlying decreases by more than the buffer amount, you will receive less than the stated principal amount and have 1-to-1 downside exposure to the decrease in the value of the underlying in excess of the buffer amount

n Investors may lose up to 85% of the stated principal amount

n All payments on the securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc.; if Citigroup Global Markets Holdings Inc. and Citigroup Inc. default on their obligations, you could lose some or all of your investment

n No periodic interest payments or dividends

n The securities will not be listed on any securities exchange and, accordingly, may have limited or no liquidity.  You should not invest in the securities unless you are willing to hold them to maturity

The securities have complex features and investing in the securities involves risks not associated with an investment in conventional debt securities. See “Summary Risk Factors” beginning on page PS-6 and “Risk Factors” beginning on page PS-5 of the accompanying product supplement and beginning on page S-1 of the accompanying prospectus supplement.

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

The securities are unsecured debt obligations issued by Citigroup Global Markets Holdings Inc. and guaranteed by Citigroup Inc.  All payments due on the securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc.  None of Wells Fargo Securities, LLC (“Wells Fargo”) or any of its affiliates will have any liability to the purchasers of the securities in the event Citigroup Global Markets Holdings Inc. defaults on its obligations under the securities and Citigroup Inc. defaults on its guarantee obligations.  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.

	Per Security	Total
Public Offering Price(1)	$1,000.00	$
Maximum Underwriting Discount and Commission(2)(3)	$25.75	$
Proceeds to Citigroup Global Markets Holdings Inc.(2)	$974.25	$

(1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least $912.00 per security, which will be less than the public offering price.  The estimated value of the securities is based on Citigroup Global Markets Inc.’s (“CGMI”) 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 any 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, an affiliate of Citigroup Global Markets Holdings Inc., as the lead agent for the offering, expects to sell the securities to Wells Fargo, as agent. Wells Fargo will receive an underwriting discount and commission of up to 2.575% ($25.75) for each security it sells. Wells Fargo may pay selected dealers, which may include Wells Fargo Advisors (“WFA”) (the trade name of the retail brokerage business of its affiliates, Wells Fargo Clearing Services, LLC and Wells Fargo Advisors Financial Network, LLC), a fixed selling commission of 1.75% ($17.50) for each security they sell.  In addition to the selling commission allowed to WFA, Wells Fargo may pay $0.75 per security of the underwriting discount and commission to WFA as a distribution expense fee for each security sold by WFA. The total underwriting discount and commission and proceeds to Citigroup Global Markets Holdings Inc. shown above give effect to the actual underwriting discount and commission provided for the sale of the securities.  See “Supplemental Plan of Distribution” below and “Use of Proceeds and Hedging” in the accompanying prospectus for further information regarding how we have hedged our obligations under the securities.

(3) In respect of certain securities sold in this offering, CGMI may pay a fee of up to $1.00 per security to selected securities dealers in consideration for marketing and other services in connection with the distribution of the securities to other securities dealers.

Citigroup Global Markets Inc. Wells Fargo Securities

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

Terms of the Securities

Underlying:	NVIDIA Corporation. The “closing value” of the underlying on any date of determination is the stock closing price of its underlying stock on that day, as provided in the accompanying product supplement. The “underlying stock” for NVIDIA Corporation is its shares of common stock. Please see the accompanying product supplement for more information.
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.
Stated Principal Amount:	$1,000 per security. References in this pricing supplement to a “security” are to a security with a stated principal amount of $1,000.
Pricing Date*:	July 18, 2025
Issue Date*:	July 23, 2025
Calculation Day*:	September 18, 2026, subject to postponement if such date is not a trading day or certain market disruption events occur as described in the accompanying product supplement.
Maturity Date*:	September 23, 2026, subject to postponement as described in the accompanying product supplement.
Maturity Payment Amount:	For each $1,000 stated principal amount security you hold at maturity: • If the ending value is greater than the starting value: $1,000 plus the lesser of: (i) $1,000 × underlying return × participation rate; and (ii) the maximum return •  If the ending value is less than or equal to the starting value, but greater than or equal to the threshold value:  $1,000; or • If the ending value is less than the threshold value: $1,000 + [$1,000 × (underlying return + buffer amount)] If the ending value is less than the threshold value, you will have 1-to-1 downside exposure to the decrease in the value of the underlying in excess of the buffer amount and will lose some, and possibly up to 85%, of the stated principal amount of your securities at maturity.
Participation Rate:	150%
Maximum Return:	At least 28.00% of the stated principal amount ($280 per security), to be determined on the pricing date. Because of the maximum return, the maturity payment amount will not exceed at least $1,280 per security.
Threshold Value:	$        , 85% of the starting value
Buffer Amount:	15%
Starting Value:	The closing value of the underlying on the pricing date
Ending Value:	The closing value of the underlying on the calculation day
Underlying Return:	(ending value – starting value) / starting value
Calculation Agent:	CGMI
Denominations:	$1,000 and any integral multiple of $1,000
CUSIP / ISIN:	17333LDB8 / US17333LDB80
* Expected. To the extent that the issuer makes any change to the expected pricing date or expected issue date, the calculation day and maturity date may also be changed in the issuer’s discretion to ensure that the term of the securities remains the same.

PS-2

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

Additional Information

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 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 in deciding whether to invest in the securities.  Certain terms used but not defined in this pricing supplement are defined in the accompanying product supplement.

When we refer to “we,” “us” and “our” in this pricing supplement, we refer only to Citigroup Global Markets Holdings Inc. and not to any of its affiliates, including Citigroup Inc.

You may access the product supplement and prospectus supplement and prospectus on the SEC website www.sec.gov as follows (or if such address has changed, by reviewing our filings for the relevant date on the SEC website):

· Product Supplement No. EA-08-02 dated March 23, 2023:
https://www.sec.gov/Archives/edgar/data/200245/000095010323004586/dp190173_424b2-wf0802.htm

· Prospectus Supplement and Prospectus, each dated March 7, 2023:
https://www.sec.gov/Archives/edgar/data/200245/000119312523063080/d470905d424b2.htm

PS-3

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

Investor Considerations

The securities are not appropriate for all investors. The securities may be an appropriate investment for investors who:

· seek leveraged exposure to the positive performance of the underlying if the ending value is greater than the starting value, subject to the maximum return;

· desire to limit the downside exposure to the underlying through the buffer amount;

· understand that if the ending value is less than the starting value by more than the buffer amount, they will receive less, and possibly significantly less, than the stated principal amount per security at maturity;

· are willing to forgo interest payments on the securities and dividends on the underlying; and

· are willing to hold the securities to maturity.

The securities may not be an appropriate investment for investors who:

· seek a liquid investment or are unable or unwilling to hold the securities to maturity;

· are unwilling to accept the risk that the value of the underlying may decrease by more than the buffer amount from the starting value to the ending value;

· seek uncapped exposure to the upside performance of the underlying;

· seek full return of the stated principal amount of the securities at maturity;

· seek current income;

· are unwilling to purchase securities with the estimated value set forth on the cover page;

· are unwilling to accept the risk of exposure to the underlying;

· seek exposure to the underlying but are unwilling to accept the risk/return trade-offs inherent in the maturity payment amount for the securities;

· are unwilling to accept the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc.; or

· prefer the lower risk of fixed income investments with comparable maturities issued by companies with comparable credit ratings.

The considerations identified above are not exhaustive. Whether or not the securities are an appropriate investment for you will depend on your individual circumstances, and you should reach an investment decision only after you and your investment, legal, tax, accounting and other advisors have carefully considered the appropriateness of an investment in the securities in light of your particular circumstances. You should also review carefully the “Summary Risk Factors” herein and the “Risk Factors” in the accompanying product supplement for risks related to an investment in the securities. For more information about the underlying, please see the information provided below.

PS-4

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

Determining Maturity Payment Amount

On the maturity date, you will receive a cash payment per security (the maturity payment amount) calculated as follows:

 

PS-5

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

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 appropriate 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 appropriateness 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” beginning on page PS-5 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 Of Your Investment.

Unlike conventional debt securities, the securities do not repay a fixed amount of principal at maturity. Instead, your maturity payment amount will depend on the performance of the underlying. If the underlying depreciates by more than the buffer amount such that the ending value is less than the threshold value, you will lose 1% of the stated principal amount of the securities for every 1% by which that depreciation exceeds the buffer amount.

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 total return on the securities at maturity is limited to the maximum return. Your return on the securities will not exceed the maximum return, even if the underlying appreciates by significantly more than the maximum return. If the underlying appreciates by more than the maximum 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 and a pass-through of dividends even if the underlying appreciates by less than the maximum return. Furthermore, the effect of the participation rate will be progressively reduced for all ending values exceeding the ending value at which the maximum return is reached.

You Will Not Receive Dividends Or Have Any Other Rights With Respect To The Underlying.

You will not receive any dividends with respect to the underlying.  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 is proposed, such as an amendment to the underlying’s organizational documents, you will not have the right to vote on such change. Any such change may adversely affect the market value of the underlying.

Your Maturity Payment Amount Depends On The Value Of The Underlying On A Single Day.

Because your maturity payment amount depends on the value of the underlying solely on the calculation day, you are subject to the risk that the 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 maturity payment amount were based on an average of values of the underlying, you might have achieved better returns.

PS-6

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

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. We have been advised that Wells Fargo currently intends to make a secondary market in relation to the securities. However, Wells Fargo may suspend or terminate making a market without notice, at any time and for any reason. If Wells Fargo suspends or terminates making a market, there may be no secondary market at all for the securities because it is likely that Wells Fargo 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, Is Less Than The Public Offering Price.

The difference is attributable to certain costs associated with selling, structuring and hedging the securities that are included in the public offering 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 and/or Wells Fargo or its 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 Wells Fargo’s Determination Of The Secondary Market Rate With Respect To Us.” 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 underlying, the dividend yields 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 Wells Fargo’s Determination Of The Secondary Market Rate With Respect To Us.

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. We expect that our internal funding rate is generally lower than Wells Fargo’s determination of the secondary market rate with respect to us, which is the rate that we expect Wells Fargo 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 Wells Fargo’s determination of the secondary market rate with respect to us, 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, Wells Fargo may determine the secondary market rate with respect to us for purposes of any purchase of the securities from you in the secondary market 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 Wells Fargo may deem appropriate.

PS-7

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

The Estimated Value Of The Securities Is Not An Indication Of The Price, If Any, At Which Any 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, we expect that any value of the securities determined for purposes of a secondary market transaction will be based on Wells Fargo’s determination of the secondary market rate with respect to us, which will likely result in a lower value for the securities than if our internal funding rate were used. In addition, we expect that 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 may be reduced by 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 public offering 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, dividend yields 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—General 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 public offering price.

We Have Been Advised That, Immediately Following Issuance, Any Secondary Market Bid Price Provided By Wells Fargo, And The Value That Will Be Indicated On Any Brokerage Account Statements Prepared By Wells Fargo 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 or Wells Fargo or its affiliates believe that investing in an instrument linked to the underlying is likely to achieve favorable returns. In fact, as we and Wells Fargo and its affiliates are each part of respective global financial institutions, our affiliates and affiliates of Wells Fargo 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 or of Wells Fargo or its 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’, Or By Wells Fargo And Its Affiliates’, Hedging And Other Trading Activities.

We expect to hedge our obligations under the securities through CGMI or other of our affiliates and/or Wells Fargo or its 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 and Wells Fargo and its affiliates may 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 values 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 or Wells Fargo and its affiliates while the value of the securities declines.

We And Our Affiliates And Wells Fargo And Its Affiliates May Have Economic Interests That Are Adverse To Yours As A Result Of Our And Their Respective Business Activities.

Our affiliates and Wells Fargo and its 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 or Wells Fargo or its affiliates while the value of the securities declines.  In addition, in the course of this business, we or our affiliates or Wells Fargo or its affiliates may acquire non-public information, which will not be disclosed to you.

PS-8

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

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—General 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.

The Securities Will Not Be Adjusted For All Events That Could Affect The Value Of The Shares Of The Underlying Stock.

Certain events may occur during the term of the securities that have a dilutive effect on the value of the shares of the underlying stock or otherwise adversely affect the market price of such shares. The calculation agent will make certain adjustments for some of these events, as described under “General Terms of the Securities” in the accompanying product supplement. However, an adjustment will not be made for all events that could have a dilutive or adverse effect on such shares or their market price, such as ordinary dividends, partial tender offers or additional public offerings of shares, and the adjustments that are made may not fully offset the dilutive or adverse effect of the particular event. Accordingly, the occurrence of any event that has a dilutive or adverse effect on the shares of the underlying stock may adversely affect what you receive at maturity or, if applicable, any other payment owed to you under the securities. Unlike an investor in the securities, a direct holder of such shares may receive an offsetting benefit from any such event that may not be reflected in an adjustment to the terms of the securities; therefore, you may experience dilution or adverse consequences in a circumstance in which a direct holder would not.

If A Reorganization Event Occurs With Respect To The Underlying Stock, The Calculation Agent May Make Adjustments To The Terms Of The Securities That Adversely Affect Your Return On The Securities.

If a reorganization event occurs with respect to the underlying stock to which the securities are linked, the calculation agent will have discretion to make such adjustments to the terms of the securities as the calculation agent determines appropriate to account for the economic effect on the securities of such event. In such an event, the calculation agent may, but is not required to, select a successor stock to which the securities may become linked thereafter. In any case, the adjustments made by the calculation agent to the terms of the securities may adversely affect the value of and your return on the securities.

The Stated Maturity Date May Be Postponed If The Calculation Day Is Postponed.

The calculation day will be postponed for non-trading days and certain market disruption events. If such a postponement occurs, the maturity date will be postponed. For more information regarding adjustments to the calculation days and payment dates and the circumstances that may result in a market disruption event, see the relevant sections of the accompanying product supplement.

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 “General Risk Factors Relating to All 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.

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Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

Hypothetical Examples and Returns

The payout profile, return table and examples below illustrate how to determine the maturity payment amount on the securities, assuming the various hypothetical ending 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 maturity payment amount on the securities will be.  The actual maturity payment amount will depend on the actual ending value.

The examples below are based on a hypothetical starting value of $100, rather than the actual starting value.  For the actual starting value, see “Terms of the Securities” above.  We have used this hypothetical value, rather than the actual value, to simplify the calculations and aid understanding of how the securities work.  However, you should understand that the actual maturity payment amount on the securities will be calculated based on the actual starting value, and not the hypothetical value indicated below. The examples below assume that the maximum return will be set at the lowest value indicated in “Terms of the Securities” above. The actual maximum return will be determined on the pricing date.

Hypothetical Payout Profile

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Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

Hypothetical Returns

Hypothetical ending value	Hypothetical underlying return	Hypothetical maturity payment amount per security	Hypothetical total pre-tax rate of return
$200.00	100.00%	$1,280.00	28.00%
$175.00	75.00%	$1,280.00	28.00%
$160.00	60.00%	$1,280.00	28.00%
$150.00	50.00%	$1,280.00	28.00%
$130.00	30.00%	$1,280.00	28.00%
$120.00	20.00%	$1,280.00	28.00%
$118.67	18.67%	$1,280.00	28.00%
$110.00	10.00%	$1,150.00	15.00%
$105.00	5.00%	$1,075.00	7.50%
$100.00	0.00%	$1,000.00	0.00%
$95.00	-5.00%	$1,000.00	0.00%
$90.00	-10.00%	$1,000.00	0.00%
$85.00	-15.00%	$1,000.00	0.00%
$80.00	-20.00%	$950.00	-5.00%
$70.00	-30.00%	$850.00	-15.00%
$60.00	-40.00%	$750.00	-25.00%
$50.00	-50.00%	$650.00	-35.00%
$25.00	-75.00%	$400.00	-60.00%
$0.00	-100.00%	$150.00	-85.00%

Hypothetical Examples

Example 1—Upside Scenario A. The hypothetical ending value is $105 (a 5% increase from the starting value), which is greater than the starting value.

Maturity payment amount per security = $1,000 plus the lesser of:

(i) $1,000 × underlying return × participation rate and (ii) the maximum return

= $1,000 + the lesser of: (i) ($1,000 × 5% × 150%) and (ii) $280

= $1,000 + the lesser of (i) $75 and (ii) $280

= $1,075

Because the underlying appreciated from the starting value to the hypothetical ending value, you would receive a total return at maturity equal to the upside performance of the underlying multiplied by the participation rate, which in this case is less than the maximum return.

Example 2—Upside Scenario B. The hypothetical ending value is $140 (a 40% increase from the starting value), which is greater than the starting value.

Maturity payment amount per security = $1,000 plus the lesser of:

(i) $1,000 × underlying return × participation rate and (ii) the maximum return

= $1,000 + the lesser of: (i) ($1,000 × 40% × 150%) and (ii) $280

= $1,000 + the lesser of (i) $600 and (ii) $280

= $1,280

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Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

Because the underlying appreciated from the starting value to the hypothetical ending value and the upside performance of the underlying multiplied by the participation rate exceeds the maximum return, your total return at maturity would be limited to the maximum return in this case. In this scenario, an investment in the securities would underperform a hypothetical alternative investment providing 1-to-1 exposure to the appreciation of the underlying without a maximum return.

Example 3—Par Scenario. The hypothetical ending value is $95 (a 5% decrease from the starting value), which is less than the starting value but greater than the threshold value.

Maturity payment amount per security = $1,000

Because the hypothetical ending value is less than the starting value but greater than the threshold value, you would be repaid the stated principal amount of your securities at maturity but would not receive any positive return on your investment.

Example 4—Downside Scenario. The hypothetical ending value is $50 (a 50% decrease from the starting value), which is less than the threshold value.

Maturity payment amount per security = $1,000 + [$1,000 × (underlying return + buffer amount)]

= $1,000 + [$1,000 × (-50% + 15%)]

= $1,000 + ($1,000 × -35%)

= $1,000 + -$350

= $650

Because the underlying depreciated from the starting value to the hypothetical ending value by more than the buffer amount, such that the hypothetical ending value is less than the threshold value, your maturity payment amount in this scenario would reflect 1-to-1 exposure to the negative performance of the underlying beyond the buffer amount.

PS-12

Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

Information About NVIDIA Corporation

NVIDIA Corporation is a full-stack computing infrastructure company with data-center-scale offerings whose full-stack includes the CUDA programming model that runs on all of its graphics processing units (GPUs), as well as domain-specific software libraries, software development kits and Application Programming Interfaces and whose data-center-scale offerings include compute and networking solutions that can scale to tens of thousands of GPU-accelerated servers interconnected to function as a single giant computer. The underlying stock of NVIDIA Corporation is registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Information provided to or filed with the SEC by NVIDIA Corporation pursuant to the Exchange Act can be located by reference to the SEC file number 000-23985 through the SEC’s website at http://www.sec.gov. In addition, information regarding NVIDIA Corporation may be obtained from other sources including, but not limited to, press releases, newspaper articles and other publicly disseminated documents. The underlying stock of NVIDIA Corporation trades on the Nasdaq Global Select Market under the ticker symbol “NVDA.”

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

The securities represent obligations of Citigroup Global Markets Holdings Inc. (guaranteed by Citigroup Inc.) only. NVIDIA 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 NVIDIA Corporation on June 25, 2025 was $154.31.

The graph below shows the closing value of NVIDIA Corporation for each day such value was available from January 2, 2020 to June 25, 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.

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Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

United States Federal Tax Considerations

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

In the opinion of our counsel, Davis Polk & Wardwell LLP, 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.  Moreover, our counsel’s opinion is based on market conditions as of the date of this preliminary pricing supplement and is subject to confirmation on the pricing date.

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

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

· Upon a sale or exchange of a security (including retirement at maturity), you should recognize 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.

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

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

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

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

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

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Market Linked Securities—Leveraged Upside Participation to a Cap and Fixed Percentage Buffered Downside Principal at Risk Securities Linked to NVIDIA Corporation due September 23, 2026

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

Pursuant to the terms of the Amended and Restated Global Selling Agency Agreement, dated April 7, 2017, CGMI, acting as principal, will purchase the securities from Citigroup Global Markets Holdings Inc. CGMI, as the lead agent for the offering, expects to sell the securities to Wells Fargo, as agent.  Wells Fargo will receive an underwriting discount and commission of up to 2.575% ($25.75) for each security it sells.  Wells Fargo may pay selected dealers, which may include WFA, a fixed selling commission of 1.75% ($17.50) for each security they sell. In addition to the selling commission allowed to WFA, Wells Fargo may pay $0.75 per security of the underwriting discount and commission to WFA as a distribution expense fee for each security sold by WFA.

In addition, in respect of certain securities sold in this offering, CGMI may pay a fee of up to $1.00 per security to selected securities dealers in consideration for marketing and other services in connection with the distribution of the securities to other securities dealers.

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.

We have been advised that, for a period of approximately three months following issuance of the securities, the price, if any, at which Wells Fargo 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 Wells Fargo or its affiliates, 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 costs associated with selling, structuring and hedging the securities that are included in the public offering price 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, Wells Fargo 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.”

© 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-15

FAQ

What is the participation rate on Citigroup’s NVIDIA-linked notes (C)?

The notes provide a 150 % participation rate in NVIDIA’s positive price moves, subject to the maximum return.

How much upside is capped for the Citigroup (C) structured note?

The maximum return is at least 28 % of principal (≥ $280 per $1,000 note).

What downside protection do investors receive on these C 424B2 notes?

There is a 15 % buffer; losses begin only if NVIDIA falls by more than 15% from the starting value.

Can I lose my entire investment in Citigroup’s NVIDIA-linked securities?

Yes. If NVIDIA declines by 85 % or more, investors could lose up to 85 % of principal at maturity.

Are the NVIDIA-linked notes insured by the FDIC?

No. The securities are unsecured and not FDIC-insured; repayment depends on Citigroup’s creditworthiness.

Will the notes pay any periodic interest or dividends?

No. The product has no periodic interest or dividend payments; all returns are delivered at maturity.