Insiders / Posner Brian S
Posner Brian S
CIK 1372455personinsider
Companies
2
First seen
Mar 10, 2026
Last activity
Jun 9, 2026
Companies
| Company | Shares held | Latest |
|---|---|---|
| Arch Capital Group Ltd. · ACGL | 122,175 | — |
| Dyne Therapeutics, Inc. · DYN | 24,500 | — |
All securities held
3 positions · latest reported per filing
| Company | Security | Shares |
|---|---|---|
| Arch Capital Group Ltd. | Common Shares, $.0011 par value per share | 122,175 |
| Dyne Therapeutics, Inc. | Common Stock | 24,500 |
| Dyne Therapeutics, Inc. | Stock option (right to buy)Derivative | 35,152 |
Activity
InsidersInstitutions
This person's insider trades (Form 4), across every company.| Date | Action | Company | Value | Shares Δ | Position after | Impact |
|---|---|---|---|---|---|---|
| Jun 3, 2026 | Sell | ACGL Arch Capital Group Ltd. Depositary Shares, Series F | $59.0K | -3K -100.00% | 0 0.00% of shares | low |
| Mar 11, 2026 | Sell | ACGL Arch Capital Group Ltd. Depositary Shares, Series G | $51.3K | -3K -60.00% | 2,000 <0.01% of shares | low |
| Mar 6, 2026 | Buy | DYN Dyne Therapeutics, Inc. Common Stock | $45.2K | +3K +35.29% | 11,500 <0.01% of shares | low |
| Jun 3, 2026 | Buy | DYN Dyne Therapeutics, Inc. Common Stock | $43.7K | +3K +12.50% | 22,500 0.01% of shares | low |
| May 20, 2026 | Buy | DYN Dyne Therapeutics, Inc. Common Stock | $42.8K | +3K +16.13% | 18,000 <0.01% of shares | low |
| Mar 11, 2026 | Buy | DYN Dyne Therapeutics, Inc. Common Stock | $38.7K | +2K +17.39% | 13,500 <0.01% of shares | low |
| May 26, 2026 | Buy | DYN Dyne Therapeutics, Inc. Common Stock | $36.4K | +2K +11.11% | 20,000 0.01% of shares | low |
| May 11, 2026 | Sell | ACGL Arch Capital Group Ltd. Depositary Shares, Series G | $34.3K | -2K -100.00% | 0 0.00% of shares | low |
| Mar 30, 2026 | Buy | DYN Dyne Therapeutics, Inc. Common Stock | $34.2K | +2K +14.81% | 15,500 <0.01% of shares | low |
| Jun 8, 2026 | Buy | DYN Dyne Therapeutics, Inc. Common Stock | $33.9K | +2K +8.89% | 24,500 0.01% of shares | low |