InsiderTrades

Posner Brian S

SEC CIK 1372455 · EDGAR

Buying vs selling by month open-market trades, last 54 months, all 3 companies
BoughtSold

Companies

TickerCompanyTitleHoldingBoughtSoldTradesFirstLast
DYNDyne Therapeutics, Inc.Dir 24.5K $274.8K — 72026-03-062026-06-08
ACGLArch Capital GroupDir 0 $91.0K $144.6K 122021-09-302026-06-03
BIIBBiogenDir 8,175 — — 12021-07-012021-07-01

Most active insiders at DYN, 12 months

#InsiderTitleBoughtSold
1 Rhodes Jason PDir —$129.10M
2 Kersten DirkDir —$38.57M
3 Cox JohnCEO, Pres, Dir —$443.7K
4 Posner Brian SDir $274.8K—
5 Kerr DouglasChief Medical Off —$233.1K
6 Lucera ErickCFO —$228.7K
7 Friedl-Naderer JohannaChief Commercial Off —$43.4K
8 Lubner David CharlesDir ——

Transactions 20

Type
Reset
X Filed Traded Ticker Company Insider Title Type Price Qty Owned ΔOwn Value
D 2026-06-09 17:06 2026-06-08 DYN Dyne Therapeutics, Inc. Posner Brian S Dir P - Purchase $16.94 +2,000 24.5K +9% +$33.9K
2026-06-05 16:10 2026-06-03 DYN Dyne Therapeutics, Inc. Posner Brian S Dir P - Purchase $17.48 +2,500 22.5K +12% +$43.7K
2026-06-04 18:23 2026-06-03 ACGL Arch Capital Group Posner Brian S Dir S - Sale $19.66 -3,000 0 -100% -$59.0K
2026-05-28 16:11 2026-05-26 DYN Dyne Therapeutics, Inc. Posner Brian S Dir P - Purchase $18.21 +2,000 20.0K +11% +$36.4K
2026-05-22 16:10 2026-05-20 DYN Dyne Therapeutics, Inc. Posner Brian S Dir P - Purchase $17.12 +2,500 18.0K +16% +$42.8K
2026-05-12 16:32 2026-05-11 ACGL Arch Capital Group Posner Brian S Dir S - Sale $17.14 -2,000 0 -100% -$34.3K
2026-05-07 16:50 2026-05-05 ACGL Arch Capital Group Posner Brian S Dir A - Grant — +2,071 122.2K +2% —
2026-04-01 16:27 2026-03-30 DYN Dyne Therapeutics, Inc. Posner Brian S Dir P - Purchase $17.08 +2,000 15.5K +15% +$34.2K
2026-03-13 2026-03-11 DYN Dyne Therapeutics, Inc. Posner Brian S Dir P - Purchase $19.35 +2,000 13.5K +17% +$38.7K
2026-03-12 2026-03-11 ACGL Arch Capital Group Posner Brian S Dir S - Sale $17.12 -3,000 2,000 -60% -$51.4K
2026-03-10 2026-03-06 DYN Dyne Therapeutics, Inc. Posner Brian S Dir P - Purchase $15.06 +3,000 11.5K +35% +$45.2K
2025-08-04 2025-08-01 ACGL Arch Capital Group Posner Brian S Dir P - Purchase $17.34 +1,000 5,000 +25% +$17.3K
2025-05-09 2025-05-07 ACGL Arch Capital Group Posner Brian S Dir A - Grant — +1,564 120.1K +1% —
2024-05-13 2024-05-09 ACGL Arch Capital Group Posner Brian S Dir A - Grant — +1,455 118.5K +1% —
2023-05-08 2023-05-04 ACGL Arch Capital Group Posner Brian S Dir A - Grant — +1,714 117.1K +1% —
2022-11-01 2022-10-28 ACGL Arch Capital Group Posner Brian S Dir P - Purchase $17.60 +2,000 4,000 +100% +$35.2K
M 2022-05-06 2022-05-04 ACGL Arch Capital Group Posner Brian S Dir A - Grant — +5,284 115.4K +5% —
2022-05-02 2022-04-29 ACGL Arch Capital Group Posner Brian S Dir P - Purchase $19.23 +2,000 2,000 New +$38.5K
2021-10-01 2021-09-30 ACGL Arch Capital Group Posner Brian S Dir D - Sale to Iss $25.00 -2,000 0 -100% -$50.0K
2021-07-02 2021-07-01 BIIB Biogen Posner Brian S Dir A - Grant $0.00 +775 8,175 +10% $0

Purchase Sale Sale after option exercise All abbreviations