花旗集团美股招股说明书(2025-09-18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 accompanyingproduct supplement, underlying supplement, prospectus supplement and prospectus are not an offer to sell these securities, nor arethey soliciting an offer to buy these securities, in any state where the offer or sale is not permitted.SUBJECT TO COMPLETION, DATED SEPTEMBER 17, 2025 October, 2025Medium-Term Senior Notes, Series NPricing Supplement No. 2025-USNCH28399Filed Pursuant to Rule 424(b)(2)Registration Statement Nos. 333-270327 and 333-270327-01 Citigroup Global Markets HoldingsInc. Autocallable Securities Linked to the Worst Performing of the Dow Jones Industrial AverageTM, theRussell 2000®Index and the S&P 500®Index Due October 8, 2030 ▪The securities offered by this pricing supplement are unsecured debt securities issued by Citigroup Global MarketsHoldings Inc. and guaranteed by Citigroup Inc. Unlike conventional debt securities, the securities do not pay interest,do not guarantee the repayment of principal at maturity and are subject to potential automatic early redemption on aperiodic basis on the terms described below. Your return on the securities will depend solely on the performance oftheworst performingof the underlyings specified below.▪The securities offer the potential for automatic early redemption at a premium following the first valuation date (other than the final valuation date) on which the closing value of the worst performing underlying on that valuation date isgreater than or equal to its autocall barrier value. If the securities are not automatically redeemed prior to maturity, thesecurities will provide for (i) repayment of the stated principal amountplusa premium at maturity if the final underlyingvalue of the worst performing underlying on the final valuation date is greater than or equal to its autocall barrier valueor (ii) repayment of the stated principal amount at maturity, with no premium, if the final underlying value of the worstperforming underlying on the final valuation date is less than its autocall barrier value but greater than or equal to itsfinal barrier value specified below.However, if the securities are not automatically redeemed prior to maturityand the final underlying value of the worst performing underlying on the final valuation date is less than itsfinal barrier value, you will lose 1% of the stated principal amount of your securities for every 1% by which itsfinal underlying value is less than its initial underlying value.▪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 downside exposure to the worst performingunderlying on the final valuation date, you will not receive dividends with respect to any underlying or participate inany 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 and Citigroup Inc. default on our obligations.Allpayments on the securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. andCitigroup Inc. If the securities are not automatically redeemed prior to maturity, you will receive atmaturity for each security you then hold:§If the final underlying value of the worst performing underlying on the final valuation Payment at maturity: date isgreater than or equal toits autocall barrier value: $1,000 + the premiumapplicable to the final valuation date§If the final underlying value of the worst performing underlying on the final valuationdate isless thanits autocall barrier value butgreater than or equal toits finalbarrier value: $1,000§If the final underlying value of the worst performing underlying on the final valuationdate isless thanits final barrier value:$1,000 + ($1,000 × the underlying return of the worst performing underlying on thefinal valuation date)If the securities are not automatically redeemed prior to maturity and the final underlying value of the worst performing underlying on the final valuation date isless than its final barrier value, you will receive significantly less than the statedprincipal amount of your securities, and possibly nothing, at maturity. (1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least$906.50 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 indicationof the price, if any, at which CGMI or any other person may be willing