杰弗里金融集团股份有限公司美国存托凭证招股说明书（2026年6月26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 isnot permitted. PRELIMINARY PRICING SUPPLEMENT(to Product Supplement no. 5, dated May 11, 2026, Prospectus Supplement dated May 11, 2026and Prospectus dated May 11, 2026) $Jefferies Jefferies Financial Group Inc.Senior Autocallable Contingent Coupon Barrier Notes due July 19, 2032 Linked to the Worst-Performing of the Dow Jones Industrial Average®, the Russell 2000® The Senior Autocallable Contingent Coupon Barrier Notes due July 19, 2032 Linked to the Worst-Performing of the Dow Jones Industrial Average®, the Russell 2000®Index and the S&P500®Index (the “Notes”) are senior unsecured obligations of Jefferies Financial Group Inc. The Notes have the terms described in the accompanying product supplement, prospectus supplement and prospectus, as supplemented or modified by this pricing supplement. The Notes are issued as part of our Series A Global Medium-Term Notes program.All payments are subject to our credit risk. If we default on our obligations, you could lose some or a significant portion of your investment. These Notes are not securedobligations and you will not have any security interest in, or otherwise have any access to, any Underlying or the securities represented by any Underlying. Jefferies Financial Group Inc.Senior Autocallable Contingent Coupon Barrier Notes due July 19, 2032 Linked to the Worst-Performing of the Dow Jones Industrial Average®, theRussell 2000®Index and the S&P 500®Index$. We may increase the Aggregate Principal Amount prior to the Original Issue Date but are not required to do so.$1,000 per Note$1,000 per NoteJuly 10, 2026July 17, 2026 (5 Business Days after the Pricing Date)Quarterly, beginning on October 12, 2026, as set forth on page PS-2. The Coupon Observation Dates are subject to postponement as described in theaccompanying 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 theaccompanying product supplement. Issuer:Title of the Notes: Aggregate Principal Amount:Issue Price:Stated Principal Amount:Pricing Date:Original Issue Date:Coupon Observation Dates: Coupon Payment Dates: Quarterly, beginning on July 12, 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 Call Observation Dates: Call Payment Dates: accompanying product supplement.July 12, 2032, subject to postponement as described in the accompanying product supplement. Valuation Date:Maturity Date: July 19, 2032, which may be postponed if the Valuation Date is postponed as described in the accompanying product supplement. The worst-performing of the Dow Jones Industrial Average®(the “INDU”), the Russell 2000®Index (the “RTY”) and the S&P 500®Index (the “SPX”).Please see “The Underlyings” below. Worst-Performing Underlying:Coupon Feature: Call Feature: Call Payment:Payment at Maturity: 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 the finalCoupon Observation Date is greater than or equal to its Coupon Barrier. General corporate purposesNone Jefferies LLC, the broker-dealer subsidiary of Jefferies Financial Group Inc., is a member of FINRA and will participate in the distribution of the notes Conflict of Interest:being offered hereby. Accordingly, the offering is subject to the provisions of FINRA Rule 5121 relating to conflicts of interest and will be conducted inaccordance with the requirements of Rule 5121. See “Conflict of Interest.”The Notes will be our senior unsecured obligations and will rank equally with our other senior unsecured indebtedness. 1An affiliate of the Issuer will pay a structuring fee of up to $6.50 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 this pricing supplement or theaccompanying product supplement, prospectus or prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.