花旗集团美股招股说明书(2025-12-18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 DECEMBER 17, 2025 December, 2025Medium-Term Senior Notes, Series NPricing Supplement No. 2025-USNCH29686Filed 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, and (ii) the value of what you receive at maturity may be significantly lessthan the stated principal amount of your securities, and may be zero. Each of these risks will depend solely on the performance of theworst performingof the underlyings specified below.▪We have the right to call the securities for mandatory redemption on any potential redemption date specified below. ▪You will be subject to risks associated with each of the underlyings and will be negatively affected by adverse movements inany one of 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. Valuation dates:January 22, 2026, February 23, 2026, March 23, 2026, April 22, 2026, May 22, 2026, June 22, 2026, July 22, 2026, August 24, 2026, September22, 2026, October 22, 2026, November 23, 2026, December 22, 2026, January 22, 2027, February 22, 2027, March 22, 2027, April 22, 2027, May24, 2027, June 22, 2027, July 22, 2027, August 23, 2027, September 22, 2027, October 22, 2027 and November 22, 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 Contingent coupon paymentdates: Contingent coupon:On each contingent coupon payment date,unless previously redeemed,the securities will pay a contingent couponequal to at least 0.725% of thestated principal amount of the securities (equivalent to a contingent coupon rate ofat least 8.70% per annum)(to be determined on the pricingdate)if and only ifthe closing value of the worst performing underlying on the immediately preceding valuation date is greater thanor equal to itscoupon barrier value.If the closing value of the worst performing underlying on any valuation date is less than its 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 redeemed prior to maturity, you will receive at maturity for each security you then hold (in addition to the final contingentcoupon payment, if applicable): ■If the final underlying value of the worst performing underlying on the final valuation date isgreater than or equal toits final barrier value:$1,000■If the final underlying value of the worst performing underlying on the final valuation date isless thanits final barrier value:$1,000 + ($1,000 × the underlying return of the worst performing underlying on the final valuation date) If the securities are not redeemed prior to maturity and the final underlying value of the worst performing underlying on the finalvaluation date is less than its final barrier value, you will receive 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. The securities will not be listed on any securities exchange (1) Citigroup Global