花旗集团美股招股说明书(2026-03-20版)

March, 2026Medium-Term Senior Notes, Series NPricing Supplement No. 2026-USNCH[ ] Citigroup Global Markets HoldingsInc. Autocallable Securities Linked to the S&P 500 Futures 35% Edge Volatility 6% Decrement Index (USD) ER Due April 3, 2036 The securities offered by this pricing supplement are unsecured debt securities issued by Citigroup Global Markets Holdings Inc. and guaranteed by Citigroup Inc. Unlike conventional debtsecurities, the securities do not pay interest, do not guarantee the repayment of principal at maturity and are subject to potential automatic early redemption on a periodic basis on the terms The securities offer the potential for automatic early redemption at a premium following the first valuation date (other than the final valuation date) on which the closing value of theunderlying is greater than or equal to the initial underlying value. If the securities are not automatically redeemed prior to maturity, the securities will provide for repayment of the statedprincipal amountplusa premium at maturity if the final underlying value is greater than or equal to the final barrier value.However, if the securities are not automatically redeemed The underlying is highly risky because it may reflect highly leveraged exposure to any decline in the S&P 500 Futures Excess Return Index. The S&P 500 Futures ExcessReturn Index tracks futures contracts on the S&P 500®Index and is likely to underperform the S&P 500®Index because of an implicit financing cost. In addition, the underlyingis subject to a decrement of 6% per annum, which will be a significant drag on its performance. You should carefully review the section “Summary Risk Factors—Risks 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 andCitigroup 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. Automatic early redemption:If, on any valuation date prior to the final valuation date, the closing value of the underlying is greater than or equal to the initial underlying value,the securities will be automatically redeemed on the fifth business day immediately following that valuation date for an amount in cash per securityequal to $1,000 plus the premium applicable to that valuation date. If the securities are automatically redeemed following any valuation date prior (1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least $850.00 per security, which will be less than the issue price. Theestimated 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 ofthe 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) 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.Investing in the securities involves risks not associated with an investment in conventional debt securities. See “Summary Risk Factors” beginning on 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 theaccompanying product supplement, underlying supplement, prospectus supplement and prospectus are truthful or complete. Any representation to the contrary is a criminal offense.You should read this pricing supplement together with the accompanying product supplement, underlying supplement, prospectus supplement and prospectus, which can be accessed via Citigroup Global Markets Holdings Inc. Additional Information The terms of the securities are set forth in the accompanying product supplement, prospectus supplement and prospectus, as supplemented bythis pricing supplement. The accompanying product supplement, prospectus supplement and prospectus contain important disclosures that arenot 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 marketdisruption events and other specified events with respect to the underlying. The accompanying underlying supplement contains importantdisclosures regarding the S&P 500®Index, on which th