Jefferies Financial Group Inc. 美股招股说明书（2026年3月19日版）

The information in this preliminary pricing supplement is not complete and may be changed without notice. This preliminary pricing supplement is not an offer tosell these securities, nor a solicitation of an offer to buy these securities, in any jurisdiction where the offering is not permitted.AMENDMENT NO. 1 TO PRELIMINARY PRICING SUPPLEMENTSUBJECT TO COMPLETION, DATED March 19, 2026 $Jefferies Jefferies Financial Group Inc.Senior Buffered Leveraged Notes due March 23, 2029 Linked to the Worst-Performing of the S&P 500®Index and the Dow Jones Industrial Average The Senior Buffered Leveraged Notes due March 23, 2029 Linked to the Worst-Performing of the S&P 500®Index and the Dow Jones Industrial Average®(the “Notes”) are seniorunsecured obligations of Jefferies Financial Group Inc.The Notes will pay no interest and have the terms described in the accompanying product supplement, prospectus supplement andprospectus, as supplemented or modified by this pricing supplement.At maturity, if the Worst-Performing Underlying hasappreciatedin value, investors will receive the Stated PrincipalAmount of their investment plus 129.00% of the upside performance of the Worst-Performing Underlying.If the Worst-Performing Underlying hasdepreciatedin value, but the Worst-Performing Underlying has not declined below its Buffer Value, investors will receive the Stated Principal Amount. However, if the Worst-Performing Underlying has declined below its BufferValue, investors will lose 1.25% of the Stated Principal Amount for every 1% decline (as compared to the Initial Value of the Worst-Performing Underlying) in the Final Value of the Worst- All payments are subject to our credit risk.If we default on our obligations, you could lose some or a significant portion of your investment.These Notes are not securedobligations and you will not have any security interest in, or otherwise have any access to, any Underlying or the securities represented by any Underlying.SUMMARY OF TERMS Jefferies Financial Group Inc.Senior Buffered Leveraged Notes due March 23, 2029 Linked to the Worst-Performing of the S&P 500®Index and the Dow Jones IndustrialAverage®$. We may increase the Aggregate Principal Amount prior to the Original Issue Date but are not required to do so.$1,000 per Note$1,000 per NoteMarch 20, 2026March 26, 2026March 31, 2026 (3 Business Days after the Pricing Date)March 20, 2029, subject to postponement as described in the accompanying product supplement. For purposes of the accompanying productsupplement, the occurrence of a Market Disruption Event or non-Index Business Day as to any Underlying will not impact any otherUnderlying that is not so affected. Issuer: Title of the Notes: Aggregate Principal Amount:Issue Price:Stated Principal AmountStrike Date: March 23, 2029, which may be postponed if the Valuation Date is postponed as described in the accompanying product supplement.The worst-performing of the S&P 500®Index (the “SPX”) and the Dow Jones Industrial Average®(the “INDU”).Please see “TheUnderlyings” below. Maturity Date:Underlying: Worst-Performing Underlying:Payment at Maturity: Stated Principal Amount × (1+ ((Underlying Return of the Worst-Performing Underlying + Buffer Amount) x Buffer Rate)).In this scenario the Payment at Maturity will be less than the Stated Principal Amount you could lose some or all of your investment.129.00% Participation Rate: Underlying Return:Initial Value:Final Value:Buffer Value:Buffer Amount:Buffer Rate:Redemption:Specified Currency:CUSIP/ISIN:Book-entry or Certificated Note:Business DayAgent:Calculation Agent:Trustee:Estimated value on the Pricing Date:Use of Proceeds:Listing:Conflict of Interest: 1An affiliate of the Issuer will pay a structuring fee of up to $8.00 per Note in connection with the distribution of the Notes to other registered broker-dealers.Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if thispricing supplement or the accompanying product supplement, prospectus or prospectus supplement is truthful or complete.Any representation to the contraryis a criminal offense. We will deliver the Notes in book-entry form only through The Depository Trust Company on or about March 31, 2026 against payment in immediately available funds. Pricing supplement dated, 2026.You should read this pricing supplement together with the related product supplement, prospectus and prospectus supplement, each of which can be accessedvia the hyperlinks below, before you decide to invest. You should rely only on the information contained in or incorporated by reference in this pricing supplement and theaccompanying product supplement, prospectus and prospectus supplement.We have not authorized anyone to provide youwith different information.We are not making an offer of these securities in any state where the offer is not permitted.You Table of Contents SPECIAL NOTE ON FORWARD-LOOK