144 0001235090 XXXXXXXX LIVE 0000011544 W R BERKLEY CORP 001-15202 475 Steamboat Road Greenwich CT 06830 2036293000 Mark Shapiro Former Board Member Common J.P. Morgan Securities LLC

390 Madison Avenue 6th Floor New York NY 10017

53375 3673268 379355841 07/28/2025 NYSE Common 06/12/2024 Compensation Issuer N 3801 06/12/2024 NA Common 06/14/2023 Compensation Issuer N 5219 06/14/2023 NA Common 06/15/2022 Compensation Issuer N 4493 06/15/2022 NA Common 06/15/2021 Compensation Issuer N 5967 06/15/2021 NA Common 06/11/2020 Compensation Issuer N 7838 06/11/2020 NA Common 06/05/2019 Compensation Issuer N 7091 06/05/2019 NA Common 05/31/2018 Compensation Issuer N 8841 05/31/2018 NA Common 05/17/2017 Compensation Issuer N 10125 05/17/2017 NA Y 07/28/2025 /s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for Mark Shapiro