杰弗瑞斯金融集团股份有限公司美国存托凭证上市说明书(2026-01-05版)

SUBJECT TO COMPLETION, DATED January 2, 2026 PRELIMINARY PRICING SUPPLEMENT (to Product Supplement no. 5, dated October 23, 2023,Prospectus Supplement dated May 12, 2023and Prospectus dated May 12, 2023) The information in this preliminary pricing supplement is not complete and may be changed without notice. This preliminary pricingsupplement is not an offer to sell these securities, nor a solicitation of an offer to buy these securities, in any jurisdiction where the offering is $Jefferies Jefferies Financial Group Inc.Senior Autocallable Contingent Coupon Barrier Notes due January 30, 2032 Linked to the Worst-Performing of the State Street® SPDR®S&P® Regional Banking ETF and the S&P 500® The Senior Autocallable Contingent Coupon Barrier Notes due January 30, 2032 Linked to the Worst-Performing of the State Street® SPDR® S&P® Regional Banking ETF and the S&P500®Index (the “Notes”) are senior unsecured obligations of Jefferies Financial Group Inc. The Notes have the terms described in the accompanying product supplement, prospectussupplement and prospectus, as supplemented or modified by this pricing supplement. The Notes are issued as part of our Series A Global Medium-Term Notes program.All payments are subject to our credit risk. If we default on our obligations, you could lose some or a significant portion of your investment. These Notes are not securedobligations and you will not have any security interest in, or otherwise have any access to, any Underlying or the securities represented by any Underlying. Issuer:Title of the Notes: Jefferies Financial Group Inc. Senior Autocallable Contingent Coupon Barrier Notes due January 30, 2032 Linked to the Worst-Performing of the State Street® SPDR® S&P®Regional Banking ETF and the S&P 500®Index$. We may increase the Aggregate Principal Amount prior to the Original Issue Date but are not required to do so. Aggregate Principal Amount:Issue Price:Stated Principal Amount:Pricing Date: January 30, 2026 (2 Business Days after the Pricing Date)Quarterly, beginning on April 28, 2026, as set forth on page PS-2. The Coupon Observation Dates are subject to postponement as described in the accompanying product supplement.As set forth on page PS-2. The Coupon Payment Dates may be postponed if the related Coupon Observation Date is postponed as described in the Coupon Payment Dates: accompanying product supplement.Quarterly, beginning on January 28, 2027, as set forth on page PS-2. The Call Observation Dates are subject to postponement as described in the Call Observation Dates: accompanying product supplement. Call Payment Dates: As set forth on page PS-2. The Call Payment Dates may be postponed if the related Call Observation Date is postponed as described in theaccompanying product supplement. Valuation Date:Maturity Date:Underlying: Worst-Performing Underlying:Coupon Feature: The Underlying with the lowest Observation Value or Final Value, as applicable, as compared to its Initial Value.Contingent Coupon Payments. The Notes will pay a Contingent Coupon Payment of $25 on the applicable Coupon Payment Date if the Observation Value of the Worst-Performing Underlying on the applicable quarterly Coupon Observation Date is greater than or equal to its Coupon Barrier.Autocallable Notes. The Notes will be automatically called if the Observation Value of the Worst-Performing Underlying on any Call Observation Date(beginning approximately one year after the Pricing Date) is equal to or greater than its Call Value. If your Notes are called, you will receive the Call Call Feature: Payment on the applicable Call Payment Date, and no further amounts will be payable on the Notes. Call Payment:Payment at Maturity: If the Final Value of the Worst-Performing Underlying is greater than or equal to its Threshold Value, you will receive for each Note that youhold a Payment at Maturity that is equal to the Stated Principal Amount If the Final Value of the Worst-Performing Underlying is less than its Threshold Value, you will receive for each Note that you hold a Payment at Maturity that is less than the Stated Principal Amount of each Note that will equal: In this scenario the Payment at Maturity will be less than the Stated Principal Amount and you could lose some or all of your investment. The Payment at Maturity will also include the final Contingent Coupon Payment if the Observation Value of the Worst-Performing Underlying on thefinal Coupon Observation Date is greater than or equal to its Coupon Barrier. Initial Value: With respect to theKRE, the ETF Closing Price of the Underlying on the Pricing Date.With respect to theSPX, the Index Closing Value of the Underlying on the Pricing Date. Observation Value: With respect to theKRE, the ETF Closing Price of the Underlyingtimesthe Adjustment Factor on the applicable Coupon Observation Date or CallObservation Date.With respect to theSPX, the Index Closing Value of the Underlying on the applicable Coupon Obse