Jefferies Financial Group Inc美股招股说明书(2025-10-08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. SUBJECT TO COMPLETION, DATED October 6, 2025 AMENDMENT NO. 1 TO PRELIMINARY PRICING SUPPLEMENT(to Product Supplement no. 5, dated October 23, 2023, Prospectus Supplement dated May 12,2023 and Prospectus dated May 12, 2023) $Jefferies Jefferies Financial Group Inc.Senior Autocallable Contingent Coupon BarrierNotes due October 31, 2031 Linked to the Worst-Performing of the Nasdaq-100 Index®, the Russell 2000®Index and the EURO STOXX 50 IndexThe Senior Autocallable Contingent Coupon BarrierNotes due October 31, 2031 Linked to the Worst-Performing of the Nasdaq-100 Index®, the Russell 2000®Index and the EURO All payments are subject to our credit risk.If we default on our obligations, you could lose some or a significant portion of your investment.These Notes are not securedobligations and you will not have any security interest in, or otherwise have any access to, any Underlying or the securities represented by any Underlying.SUMMARY OF TERMS Senior Autocallable Contingent Coupon BarrierNotes due October 31, 2031 Linked to the Worst-Performing of the Nasdaq-100Index®, the Russell 2000®Index and the EURO STOXX 50 Index®$. 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 AmountPricing Date:Original Issue Date:Coupon Observation Dates: October 31, 2025 (2 Business Days after the Pricing Date)Monthly, beginning on December 1, 2025, as set forth on page PS-3. The Coupon Observation Dates are subject to postponement as described in the accompanying product supplement.As set forth on page PS-3. The Coupon Payment Dates may be postponed if the related Coupon Observation Date is postponed as described in the accompanying product supplement. Coupon Payment Dates: Call Observation Dates: Monthly, beginning on October 29, 2026, as set forth on page PS-3. The Call Observation Dates are subject to postponement asdescribed in the accompanying product supplement.As set forth on page PS-3. The Call Payment Dates may be postponed if the related Call Observation Date is postponed as Call Payment Dates: described in the accompanying product supplement.October 29, 2031, subject to postponement as described in the accompanying product supplement. Valuation Date:Maturity Date: October 31, 2031, which may be postponed if the Valuation Date is postponed as described in the accompanying productsupplement.The worst-performing of the Nasdaq-100 Index® (the “NDX”), the Russell 2000®Index (the “RTY”) and the EURO STOXX 50 Index®(the “SX5E”).Please see “The Underlyings” below.The Underlying with the lowest Observation Value or Final Value, as applicable, as compared to its Initial Value Underlying: Worst-Performing Underlying:Coupon Feature: Contingent Coupon Payments. The Notes will pay a Contingent Coupon Payment of $8.125 on the applicable Coupon PaymentDate if the Observation Value of the Worst-Performing Underlying on the applicable monthly 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 Call Feature: Observation Date (beginning approximately one year after the Pricing Date) is equal to or greater than its Call Value.If your Notesare called, you will receive the Call Payment on the applicable Call Payment Date, and no further amounts will be payable on theNotes.The Stated Principal Amountplusany Contingent Coupon Payment that may otherwise be due on the applicable Call Payment Call Payment: Date.If the Final Value of the Worst-Performing Underlying is greater than or equal to its Threshold Value, you will receive for Payment at Maturity: each Note that you hold a Payment at Maturity that is equal to the Stated Principal AmountIf 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 final Coupon Observation Date is greater than or equal to its Coupon Barrier.With respect to each Underlying, the Index Closing Value of the Underlying on the Pricing Date. With respect to each Underlying, the Index Closing Value of the Underlying on the applicable Coupon Observation Date or CallObservation Date.With res