Summary Prospectus by Investment Company (Form 497K)

FIST2-P1 11/26

FRANKLIN INVESTORS SECURITIES TRUST

SUPPLEMENT DATED NOVEMBER 3, 2026

TO THE SUMMARY PROSPECTUS AND PROSPECTUS

EACH DATED MARCH 1, 2026, OF

FRANKLIN LOW DURATION TOTAL RETURN FUND (the "Fund")

To pursue its investment goal, the Fund regularly enters into various currency derivative transactions, including currency forwards, currency futures, currency options and currency swaps; various interest rate derivative transactions, including interest rate/bond futures and options thereon, interest rate swaps and options thereon, interest rate swap indices and inflation index swaps; and various credit derivative transactions, including credit default swaps, credit default swap indexes, credit default swap index tranches, options on credit default swaps and fixed income total return swaps. In addition the Fund may enter into options on exchange-traded funds and mutual funds. The use of these derivative transactions may allow the Fund to obtain net long or short exposures to select currencies, interest rates, countries, duration or credit risks. These derivatives may be used to enhance Fund returns, increase liquidity, gain exposure to certain instruments or markets in a more efficient or less expensive way and/or hedge risks associated with its other portfolio investments. The Fund may, at times, have significant exposure to treasury futures.

To pursue its investment goal, the Fund regularly enters into various currency derivative transactions, including currency and cross currency forwards, currency and currency index futures contracts, currency options and currency swaps. In addition, the Fund regularly enters into various interest rate derivative transactions, interest rate/bond futures and options thereon, interest rate swaps and options thereon, interest rate swap indices and inflation index swaps. To pursue its investment goal, the Fund also regularly enters into various credit derivative transactions, including credit default swaps, credit default swap indexes, credit default swap index tranches, options on credit default swaps and fixed income total return swaps. In addition the Fund may enter into options on exchange-traded funds and mutual funds. The use of these derivative transactions may allow the Fund to obtain net long or net negative (short) exposures to select currencies, interest rates, countries, duration or credit risks. These derivatives may be used to enhance Fund returns, increase liquidity, gain exposure to certain instruments or markets in a more efficient or less expensive way and/or hedge risks associated with its other portfolio investments. The results of such transactions may also represent, from time to time, a significant component of the Fund's investment returns. The Fund may, at times, have significant exposure to treasury futures.

Swap agreements, such as interest rate, fixed income total return, currency, inflation index and credit default swaps, are contracts between the Fund and another party (the swap counterparty) involving the exchange of payments on specified terms over periods ranging from a few days to multiple years.

Please retain this supplement for future reference.