Posner Brian S
- SEC CIK
- 0001372455
In the past year, 7 open-market purchase filings worth $274.8K and 3 sale filings worth $144.6K.
Current role at each company
- DYN Dyne Therapeutics, Inc.Directoras of Jun 9, 2026
- ACGL Arch Capital Group Ltd.Directoras of Jun 4, 2026
- BIIB Biogen Inc.Directoras of Jul 2, 2021
Open-market trades in the past year
Open-market purchases (P) and sales (S) filed in the last 365 days, not counting derivative securities or duplicate filings. Values leave out price outliers.
- Bought
- $274.8K
- 7 filings
- Sold
- $144.6K
- 3 filings
- Net
- +$130.2K
- Bought minus sold
- Companies
- 2
- With open-market trades
Trades
Every Form 4 that lists Posner Brian S as a reporting owner, including filings made jointly with others, grouped by company. Each row adds up one type of transaction in one filing. Only open-market purchases (P) and sales (S) are shown by default.
DYN Dyne Therapeutics, Inc.
Director7 trades
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Jun 9, 2026 (view filing) | Jun 8 | 1 day | Posner Brian SDirector | PPurchase | +2.00K | $16.94 | +$33.9K | +8.9%24.5K after | |
| Jun 5, 2026 (view filing) | Jun 3 | 2 days | Posner Brian SDirector | PPurchase | +2.50K | $17.48 | +$43.7K | +12.5%22.5K after | |
| May 28, 2026 (view filing) | May 26 | 2 days | Posner Brian SDirector | PPurchase | +2.00K | $18.21 | +$36.4K | +11.1%20.0K after | |
| May 22, 2026 (view filing) | May 20 | 2 days | Posner Brian SDirector | PPurchase | +2.50K | $17.12 | +$42.8K | +16.1%18.0K after | |
| Apr 1, 2026 (view filing) | Mar 30 | 2 days | Posner Brian SDirector | PPurchase | +2.00K | $17.08 | +$34.2K | +14.8%15.5K after | |
| Mar 13, 2026 (view filing) | Mar 11 | 2 days | Posner Brian SDirector | PPurchase | +2.00K | $19.35 | +$38.7K | +17.4%13.5K after | |
| Mar 10, 2026 (view filing) | Mar 6 | 4 days | Posner Brian SDirector | PPurchase | +3.00K | $15.06 | +$45.2K | +35.3%11.5K after |
ACGL Arch Capital Group Ltd.
Director6 trades
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Jun 4, 2026 (view filing) | Jun 3 | 1 day | Posner Brian SDirector | SSaleDepositary Shares, Series F | −3.00K | $19.66 | −$59.0K | −100.0%0 after | |
| May 12, 2026 (view filing) | May 11 | 1 day | Posner Brian SDirector | SSaleDepositary Shares, Series G | −2.00K | $17.14 | −$34.3K | −100.0%0 after | |
| Mar 12, 2026 (view filing) | Mar 11 | 1 day | Posner Brian SDirector | SSaleDepositary Shares, Series G | −3.00K | $17.12 | −$51.4K | −60.0%2.00K after | |
| Aug 4, 2025 (view filing) | Aug 1 | 3 days | Posner Brian SDirector | PPurchaseDepositary Shares, Series G | +1.00K | $17.34 | +$17.3K | +25.0%5.00K after | |
| Nov 1, 2022 (view filing) | Oct 28 | 4 days | Posner Brian SDirector | PPurchaseDepositary Shares, Series G | +2.00K | $17.60 | +$35.2K | +100.0%4.00K after | |
| May 2, 2022 (view filing) | Apr 29 | 3 days | Posner Brian SDirector | PPurchaseDepositary Shares, Series G | +2.00K | $19.23 | +$38.5K | New position2.00K after |