花旗集团美股招股说明书(2026-05-12版)

The information in this preliminary pricing supplement is not complete and may be changed. A registration statement relating to thesesecurities has been filed with the Securities and Exchange Commission. This preliminary pricing supplement and the accompanyingprospectus supplement and prospectus are not an offer to sell these securities, nor are they soliciting an offer to buy these securities, inany state where the offer or sale is not permitted.SUBJECT TO COMPLETION, DATED MAY 11, 2026Citigroup Global Markets HoldingsMay, 2026 Medium-Term Senior Notes, Series NPricing Supplement No. 2026-USNCH31915Filed Pursuant to Rule 424(b)(2)Registration Statement Nos. 333-293732 and 333-293732-02Principal-at-Risk Securities Linked to the Synthetic 5Y5Y SOFR CMS Rate Due August 13, 2026 Inc. ▪ 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 debt securities, the securities do not pay interestand do not repay a fixed amount of principal at maturity.Instead, the securities offer a payment at maturity that may begreater than, equal to or less than the issue price, depending on the synthetic 5Y5Y SOFR CMS rate on the valuationdate.The synthetic 5Y5Y SOFR CMS rate on any date is intended to represent the USD SOFR ICE swap rate for the 5-year period starting 5 years from the current date.We refer to this rate as “synthetic” because it is not a directly market-observable rate, and for purposes of the securities is calculated “synthetically” using a formula based on the 10-yearUSD SOFR ICE swap rate and the 5-year USD SOFR ICE swap rate on the current date, as specified in more detailbelow.▪ Investors will receive the maximum payment at maturity specified below only if the synthetic 5Y5Y SOFR CMS rate on the valuation date is less than or equal to the strike specified below.If the synthetic 5Y5Y SOFR CMS rate on thevaluation date is greater than the strike, investors will receive less than the maximum payment at maturity and mayreceive less, and possibly significantly less, than the stated principal amount.In that instance, the greater the differencebetween the synthetic 5Y5Y SOFR CMS rate on the valuation date and the strike, the lower your payment at maturity,subject to the minimum payment at maturity.If the synthetic 5Y5Y SOFR CMS rate on the valuation date is greater thanthe strike by an amount that is equal to or greater than the OTM strike width specified below, investors will receive onlythe minimum payment at maturity specified below, representing a significant loss on an investment in the securities.▪The securities are highly risky investments.A relatively small increase in the synthetic 5Y5Y SOFR CMS rate as of the valuation date compared to the strike will result in the loss of a significant portion of your investment.▪ 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 amount due under the securities if we and Citigroup Inc. default on our obligations.All paymentson the securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc.KEY TERMS (1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing datewill be between $970.00 and $1,000.00 per security, which may be less than the issue price. The estimated value of thesecurities is based on CGMI’s proprietary pricing models and our internal funding rate. It is not an indication of actual profitto CGMI or other of our affiliates, nor is it an indication of the price, if any, at which CGMI or any other person may bewilling to buy the securities from you at any time after issuance. See “Valuation of the Securities” in this pricingsupplement.(2) For more information on the distribution of the securities, see “Supplemental Plan of Distribution” in this pricing supplement.CGMI and its affiliates may profit from expected hedging activity related to this offering, even if the value ofthe 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 “Risk Factors Relating to the Securities” beginning on page PS-4.Neither the Securities and Exchange Commission (the “SEC”) nor any state securities commission has approved or disapproved of the securities or determined that this pricing supplement and the accompanying prospectussupplement and prospectus is truthful or complete. Any representation to the contrary is a criminal offense.You should read this pricing supplement together with the accompanying prospectus supplement andprospectus, each of which can be accessed via the hyperlink below:Prospectus Supplement and Prospectus each dated February 25, 2026The securities are not bank deposits and are not in