花旗集团美股招股说明书(2025-06-13版)

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 andExchange Commission. This preliminary pricing supplement and the accompanying product supplement, prospectus supplement and prospectus are not an offer to sell these securities,nor are they soliciting an offer to buy these securities, in any state where the offer or sale is not permitted.SUBJECT TO COMPLETION, DATED JUNE 12, 2025 June, 2025Medium-Term Senior Notes, Series NPricing Supplement No. 2025-USNCH27216Filed Pursuant to Rule 424(b)(2)Registration Statement Nos. 333-270327 and 333-270327-01 Citigroup Global Markets Holdings Enhanced Barrier Digital Securities Linked to Stanley Black & Decker, Inc. Due July 23, 2026▪ The securities offered by this pricing supplement are unsecured debt securities issued by Citigroup Global Markets Holdings Inc. and guaranteed by Citigroup Inc. Unlike conventional debtsecurities, the securities do not pay interest and do not repay a fixed amount of principal at maturity. Instead, the securities offer a payment at maturity with a value that may be greater thanor less than the stated principal amount, depending on the performance of the underlying specified below from the initial underlying value to the final underlying value.▪ The securities offer modified exposure to the performance of the underlying, with a digital (fixed) return at maturity so long as the final underlying value is greater than or equal to the finalbarrier value. In exchange, investors in the securities must be willing to forgo (i) any appreciation of the underlying in excess of the digital return and (ii) any dividends with respect to theunderlying. In addition, investors in the securities must be willing to accept full downside exposure to the depreciation of the underlying if the final underlying value is less than the finalbarrier value.If the final underlying value is less than the final barrier value, you will not be repaid the stated principal amount of your securities at maturity and, instead, willreceive underlying shares of the underlying (or, in our sole discretion, cash based on the value thereof) that will be worth significantly less than your initial investment andpossibly worth nothing. You may lose your entire investment in the securities.▪ In order to obtain the modified exposure to the underlying that the securities provide, investors must be willing to accept (i) an investment that may have limited or no liquidity and (ii) therisk of not receiving any amount due under the securities if we and Citigroup Inc. default on our obligations.All payments on the securities are subject to the credit risk of CitigroupGlobal Markets Holdings Inc. and Citigroup Inc. If the final underlying value is less than the final barrier value, you will receive underlying shares (or, in our solediscretion, cash) that will be worth significantly less than the stated principal amount of your securities, and possiblynothing, at maturity. $140.00 per security (representing a digital return equal to 14.00% of the stated principal amount). You will receive the digitalreturn amount only if the final underlying value is greater than or equal to the final barrier value. (i) The final underlying valueminusthe initial underlying value,divided by(ii) the initial underlying value (1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least $926.00 per security, which will be less than theissue 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 ouraffiliates, 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 theSecurities” in this pricing supplement. (2) CGMI will receive an underwriting fee of up to $11.00 for each security sold in this offering. The total underwriting fee and proceeds to issuer in the table above give effect to the actualtotal underwriting fee. From this underwriting fee, CGMI will pay selected dealers not affiliated with CGMI a selling concession of $10.00 for each security they sell and a structuring fee ofup to $1.00 for each security they sell. For more information on the distribution of the securities, see “Supplemental Plan of Distribution” in this pricing supplement. In addition to theunderwriting 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” inthe accompanying prospectus. (3) The per security proceeds to issuer indicated above represent the minimum per security proceeds to issuer for any security, assuming the maximum per security underwriting fee.