| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| MITSUI SUMITOMO INSURANCE CO LTD | 10%+ Owner | 9, KANDA-SURUGADAI 3-CHOME, CHIYODA-KU, TOKYO, JAPAN | MITSUI SUMITOMO INSURANCE CO., LTD., By: /s/ Hironori Morimoto, Name: Hironori Morimoto, Title: Authorized Signatory | 29 Dec 2025 | 0001142206 |
| MS&AD Insurance Group Holdings, Inc. | 10%+ Owner | TOKYO SUMITOMO TWIN BUILDING WEST TOWER,, 27-2, SHINKAWA 2-CHOME, CHUO-KU,, TOKYO, JAPAN | MS&AD INSURANCE GROUP HOLDINGS, INC., By: /s/ Hironori Morimoto, Name: Hironori Morimoto, Title: Authorized Signatory | 29 Dec 2025 | 0001431048 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | WRB | Common Stock | Purchase | $16,350,449 | +232,546 | +0.47% | $70.31 | 49,444,484 | 23 Dec 2025 | Direct | F1, F2, F3 |
| transaction | WRB | Common Stock | Purchase | $144,228 | +2,027 | +0% | $71.15 | 49,446,511 | 23 Dec 2025 | Direct | F1, F3, F4 |
| transaction | WRB | Common Stock | Purchase | $15,512,046 | +220,000 | +0.44% | $70.51 | 49,666,511 | 24 Dec 2025 | Direct | F1, F3, F5 |
| transaction | WRB | Common Stock | Purchase | $15,522,760 | +220,000 | +0.44% | $70.56 | 49,886,511 | 26 Dec 2025 | Direct | F1, F3, F6 |
| transaction | WRB | Common Stock | Purchase | $14,508,383 | +205,000 | +0.41% | $70.77 | 50,091,511 | 29 Dec 2025 | Direct | F1, F3, F7 |
Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.
Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).
| Id | Content |
|---|---|
| F1 | The purchases reported on this Form 4 were effected pursuant to a Rule 10b5-1 purchase plan, adopted October 3, 2025. |
| F2 | 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. |
| F3 | 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. |
| F4 | The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $71.06 to $71.18. |
| F5 | The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $70.13 to $70.64. |
| F6 | The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $70.30 to $70.9844. |
| F7 | The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $70.535 to $70.989. |
MSI, the Issuer and WR Berkley & Others LLC ("WRBO") are party to certain agreements described in, and filed as exhibits to, the Reporting Persons' Schedule 13D filed with the U.S. Securities and Exchange Commission on December 11, 2025. The Reporting Persons disclaim beneficial ownership of the securities of the Issuer owned by WRBO and disclaim that the Reporting Persons and WRBO constitute a "group" within the meaning of Rule 13d-5(b)(1) under the Securities Exchange Act of 1934, as amended.