花旗集团美股招股说明书(2025-12-15版)

The information in this preliminary pricing supplement is not complete and may be changed. A registration statementrelating to these securities has been filed with the Securities and Exchange Commission. This preliminary pricingsupplement and the accompanying product supplement, underlying supplement, prospectus supplement and prospectus SUBJECT TO COMPLETION, DATED DECEMBER 15, 2025December, 2025Medium-Term Senior Notes, Series NPricing Supplement No. 2025-USNCH29650Filed Pursuant to Rule 424(b)(2)Registration Statement Nos. 333-270327 and 333-270327-01 Citigroup Global Markets HoldingsInc. Callable Contingent Coupon Equity Linked Securities Linked to the Worst Performing of the Nasdaq- The securities offered by this pricing supplement are unsecured debt securities issued by Citigroup Global MarketsHoldings Inc. and guaranteed by Citigroup Inc. The securities offer the potential for periodic contingent couponpayments at an annualized rate that, if all are paid, would produce a yield that is generally higher than the yield on ourconventional debt securities of the same maturity. In exchange for this higher potential yield, you must be willing toaccept the risks that (i) your actual yield may be lower than the yield on our conventional debt securities of the same 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 adversemovements inany one of the underlyings. Although you will have downside exposure to the worst performing risk of not receiving any payments due under the securities if we and Citigroup Inc. default on our obligations.Allpayments on the securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and If the final underlying value of the worst performing underlying on the final valuation date isless thanits final barrier value: (1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least$932.50 per security, which will be less than the issue price. The estimated value of the securities is based on CGMI’s proprietarypricing 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 and its affiliates may profit from expected hedging activity related to this offering, even if the value of the securities declines. See “Useof Proceeds and Hedging” in the accompanying prospectus. Investing in the securities involves risks not associated with an investment in conventionaldebt securities. See “Summary Risk Factors” beginning on page PS-6. Neither the Securities and Exchange Commission nor any state securities commission has approved ordisapproved of the securities or determined that this pricing supplement and the accompanying productsupplement, underlying supplement, prospectus supplement and prospectus are truthful or complete. Any supplement, prospectus supplement and prospectus, which can be accessed via the hyperlinks below:Product Supplement No. EA-04-10 dated March 7, 2023 Underlying Supplement No. 11 dated March 7, 2023Prospectus Supplement and Prospectus each dated March 7, 2023The 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. Additional Information The terms of the securities are set forth in the accompanying product supplement, prospectus supplement andprospectus, as supplemented by this pricing supplement. The accompanying product supplement, prospectus supplementand prospectus contain important disclosures that are not repeated in this pricing supplement. For example, theaccompanying product supplement contains important information about how the closing value of each underlying will bedetermined 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 each underlying. The accompanying underlying supplement Hypothetical Examples The examples in the first section below illustrate how to determine whether a contingent coupon will be paid following avaluation date. The examples in the second section below illustrate how to determine the payment at maturity on thesecurities, assuming the securities are not redeemed prior to maturity. The examples are solely for illustrative purposes, The examples below are based on the following hypothetical values and do not reflect the actual initial underlying values,coupon barrier values or final barrier values of the underlyings. For the actual initial underlying value, coupon barrier valueand final barrier value of each underlying, see the cover page of this pricing supplement. We have used these hypotheticalvalues, rather than the act