Jefferies Financial Group Inc.美国存托凭证招股说明书（2026年3月6日版）

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 PRELIMINARY PRICING SUPPLEMENT(to Product Supplement no. 5, dated October 23, 2023, SUBJECT TO COMPLETION, DATED March 5, 2026 Prospectus Supplement dated May 12, 2023and Prospectus dated May 12, 2023) Jefferies Jefferies Financial Group Inc. Senior Autocallable Barrier Notes due March 12, 2031Linked to the Worst-Performing of the Nasdaq-100 Index®, the Russell 2000® The Senior Autocallable Barrier Notes due March 12, 2031 Linked to the Worst-Performing of the Nasdaq-100 Index®, the Russell 2000®Index and the S&P 500®Index (the “Notes”) aresenior unsecured obligations of Jefferies Financial Group Inc. The Notes have the terms described in the accompanying product supplement, prospectus supplement and prospectus, assupplemented 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 secured obligations 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.Title of the Notes:Senior Autocallable Barrier Notes due March 12, 2031 Linked to the Worst-Performing of the Nasdaq-100 Index®, the Russell 2000®Index and the S&P500®IndexAggregate Principal Amount:$. We may increase the Aggregate Principal Amount prior to the Original Issue Date but are not required to do so.$1,000 per Note Issue Price:Stated Principal Amount:Strike Date:Pricing Date:Original Issue Date:Call Observation Dates: $1,000 per NoteMarch 5, 2026March 9, 2026March 12, 2026 (3 Business Days after the Pricing Date)Annually, beginning on March 9, 2027, as set forth on page PS-2. The Call Observation Dates are subject to postponement as described in theaccompanying product supplement. 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 the accompanyingproduct supplement. Call Payment Dates: March 7, 2031 (which is also the final Call Observation Date), subject to postponement as described in the accompanying product supplement.March 12, 2031, which may be postponed if the Valuation Date is postponed as described in the accompanying product supplement.The worst-performing of the Nasdaq-100 Index®(the “NDX”), the Russell 2000®Index (the “RTY”) and the S&P 500®Index (the “SPX”). Please see “The Valuation Date:Maturity Date: Worst-PerformingUnderlying: 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 applicableCall Payment on the applicable Call Payment Date, and no further amounts will be payable on the Notes. The Call Premium applicable to each Call Observation Date is set forth on page PS-2 and reflects a return of approximately 13.00% per annum. The Notesare “Snowball Coupon Notes” for purposes of the accompanying product supplement and, for purposes of this pricing supplement, references in theaccompanying product supplement to “Snowball Coupon Payment” shall be deemed to refer to “Call Premium”. Payment at Maturity: If the Notes are not called prior to maturity and the Final Value of the Worst-Performing Underlying is greater than or equal to its Threshold Value, you will receive for each Note that you hold a Payment at Maturity that is equal to the Stated Principal AmountIf the Notes are not called prior to maturity and 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: Initial Value:Observation Value:Final Value:Call Value: Threshold Value:Specified Currency:CUSIP/ISIN:Book-entry or CertificatedNote:Business Day:Agent:Calculation Agent:Trustee:Estimated value on thePricingDate:Use of Proceeds:Listing: New YorkJefferies LLC, a wholly-owned subsidiary of Jefferies Financial Group Inc. See “Supplemental Plan of Distribution.” Jefferies Financial Services, Inc., a wholly owned subsidiary of Jefferies Financial Group Inc.The Bank of New York MellonApproximately $989.50 per Note, or within $30.00 of that estimate. Please see “The Notes” below. General corporate purposesNone Conflict of Interest:Jefferies LLC, the broker-dealer subsidiary of Jefferies Financial Group Inc., is a member of FINRA and w