Transaction Details

Footnotes

The purchases reported on this Form 4 were effected pursuant to a Rule 10b5-1 purchase plan, adopted October 3, 2025. | The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $70.1731 to $70.99. The Reporting Persons undertake to provide to W.R. Berkley Corporation (the "Issuer"), any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote and in footnotes 4, 5, 6 and 7. | The shares are held directly by Mitsui Sumitomo Insurance Co., Ltd. ("MSI"). Because MSI is a wholly-owned subsidiary of MS&AD Insurance Group Holdings, Inc. ("MS&AD"), MS&AD may be deemed to beneficially own the reported securities. MS&AD expressly disclaims beneficial ownership of the reported securities, except to the extent of its pecuniary interest therein. | The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $71.06 to $71.18. | The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $70.13 to $70.64. | The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $70.30 to $70.9844. | The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $70.535 to $70.989.