Brian S. Posner

Insider Reports History

Location
14 Cambridge Center, Cambridge, MA
Signature
/s/ Ron Caponigro, Attorney-in-Fact
All insider transactions
Transactions in reports broken out by “transaction date” reported in original SEC filing, see here for transactions aggregated across transaction date

Holdings reported by Brian S. Posner:

Stock Role Class Num Shares Value Price $ Report Date Ownership
ARCH CAPITAL GROUP LTD. Director Common Shares, $.0011 par value per share 120K $11.2M $93.00 Aug 1, 2025 Direct
BIOGEN INC. Director Common Stock 8.03K $1.99M $248.00 Jun 7, 2022 Direct
Dyne Therapeutics, Inc. Director Common Stock 8.5K $107K $12.58 Oct 1, 2025 Direct
ARCH CAPITAL GROUP LTD. Director Depositary Shares, Series G 5K $86.7K $17.34 Aug 1, 2025 Direct
Dyne Therapeutics, Inc. Director Stock option (right to buy) 70K Oct 1, 2025 Direct
ARCH CAPITAL GROUP LTD. Director Depositary Shares, Series F 3K Aug 1, 2025 Direct

Insider Reports Filed by Brian S. Posner

Symbol Company Period Transactions Value $ Form Type Date Filed Role
DYN Dyne Therapeutics, Inc. Oct 1, 2025 1 $0 4 Oct 2, 2025 Director
DYN Dyne Therapeutics, Inc. Oct 1, 2025 0 $0 3 Oct 2, 2025 Director
ACGL ARCH CAPITAL GROUP LTD. Aug 1, 2025 1 $17.3K 4 Aug 4, 2025 Director
ACGL ARCH CAPITAL GROUP LTD. May 7, 2025 1 $0 4 May 9, 2025 Director
ACGL ARCH CAPITAL GROUP LTD. May 9, 2024 1 $0 4 May 13, 2024 Director
ACGL ARCH CAPITAL GROUP LTD. May 4, 2023 1 $0 4 May 8, 2023 Director
BIIB BIOGEN INC. Dec 31, 2022 1 $0 5 Jan 27, 2023 Director
ACGL ARCH CAPITAL GROUP LTD. Oct 28, 2022 1 $35.2K 4 Nov 1, 2022 Director
ACGL ARCH CAPITAL GROUP LTD. May 4, 2022 2 $0 4 May 6, 2022 Director
ACGL ARCH CAPITAL GROUP LTD. Apr 29, 2022 1 $38.5K 4 May 2, 2022 Director
ACGL ARCH CAPITAL GROUP LTD. Sep 30, 2021 1 -$50K 4 Oct 1, 2021 Director
BIIB BIOGEN INC. Jul 1, 2021 1 $0 4 Jul 2, 2021 Director
ACGL ARCH CAPITAL GROUP LTD. Jun 14, 2021 1 -$101K 4 Jun 15, 2021 Director
BIIB BIOGEN INC. Jun 4, 2021 1 -$98.7K 4 Jun 7, 2021 Director
ACGL ARCH CAPITAL GROUP LTD. May 6, 2021 2 $0 4 May 10, 2021 Director