花旗集团美股招股说明书(2025-10-06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, underlying supplement, prospectus supplement and prospectus are not an offerto 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 OCTOBER 3, 2025October, 2025 Medium-Term Senior Notes, Series NPricing Supplement No. 2025-USNCH28742Filed Pursuant to Rule 424(b)(2)Registration Statement Nos. 333-270327 and 333-270327-01 Citigroup Global Markets Holdings ▪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 thepotential 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 securitiesof 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 debtsecurities 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 thanthe 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 autocalldate specified below. Each of these risks will depend solely on the performance of theworst performingof the underlyings specified below.▪ You will be subject to risks associated witheachof the underlyings and will be negatively affected by adverse movements inany oneof the underlyings. Although you will have downsideexposure to the worst performing underlying, you will not receive dividends with respect to any underlying or participate in any appreciation of any 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 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. November 10, 2025, December 9, 2025, January 9, 2026, February 9, 2026, March 9, 2026, April 9, 2026, May 11, 2026, June 9, 2026, July 9,2026, August 10, 2026, September 9, 2026, October 9, 2026, November 9, 2026, December 9, 2026, January 11, 2027, February 9, 2027, March 9,2027, April 9, 2027, May 10, 2027, June 9, 2027, July 9, 2027, August 9, 2027, September 9, 2027 and October 11, 2027 (the “final valuationdate”), each subject to postponement if such date is not a scheduled trading day or certain market disruption events occur The third business day after each valuation date, except that the contingent coupon payment date following the final valuation date will be thematurity date On each contingent coupon payment date,unless previously redeemed,the securities will pay a contingent couponequal to 0.65% to 0.6583% ofthe stated principal amount of the securities (equivalent to a contingent coupon rate ofapproximately7.80% to 7.90% per annum)(to bedetermined on the pricing date)if and only ifthe closing value of the worst performing underlying on the immediately preceding valuation date isgreater thanor equal to itscoupon barrier value.If the closing value of the worst performing underlying on any valuation date is less thanits coupon barrier value, you will not receive any contingent coupon payment on the immediately following contingent coupon paymentdate. If the closing value of the worst performing underlying on one or more valuation dates is less than its coupon barrier value and, ona subsequent valuation date, the closing value of the worst performing underlying on that subsequent valuation date is greater than orequal to its coupon barrier value, your contingent coupon payment for that subsequent valuation date will include all previously unpaidcontingent coupon payments (without interest on amounts previously unpaid). However, if the closing value of the worst performingunderlying on a valuation date is less than its coupon barrier value and the closing value of the worst performing underlying on eachsubsequent valuation date up to and including the final valuation date is less than its coupon barrier value, you will not receive theunpaid contingent coupon payments in respect of those valuation dates. 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 finalcontingent coupon payment, if applica