Posner Brian S bought Dyne Therapeutics ($DYN) shares on the open market twice in the last year, totaling $83,880, with the latest purchase on March 11, 2026. These buys rank 2,564th among 4,983 insiders in our database, where the average is $1.46 million across 3.29 transactions. He made no open market sales in the period.
| Transaction Date | Company | Ticker | Insider Name | Title | Transaction Type | Security | Shares | Price | Shares Owned Following | Total Shares Outstanding | % of Owned | % of Outstanding |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| March 30, 2026 | Dyne Therapeutics, Inc. | $DYN | Posner Brian S | Not found | P | Common Stock | 2000 | $17.08 | 15,500.0000 | 142,824,687 | 14.81% | 0.00% |
| March 11, 2026 | Dyne Therapeutics, Inc. | $DYN | Posner Brian S | Not found | P | Common Stock | 2000 | $19.35 | 13,500.0000 | 142,824,687 | 17.39% | 0.00% |
| March 11, 2026 | ARCH CAPITAL GROUP LTD. | $ACGL | Posner Brian S | Director | S | Depositary Shares, Series G | 3000 | $17.12 | 2,000.0000 | 379,100,000 | 60.00% | 0.00% |
| March 6, 2026 | Dyne Therapeutics, Inc. | $DYN | Posner Brian S | Not found | P | Common Stock | 3000 | $15.06 | 11,500.0000 | 142,824,687 | 35.29% | 0.00% |
| Oct. 1, 2025 | Dyne Therapeutics, Inc. | $DYN | Posner Brian S | Not found | A | Stock option (right to buy) | 70000 | $0.00 | 70,000.0000 | 113,121,357 | 9999.99% | 0.06% |
| Aug. 1, 2025 | ARCH CAPITAL GROUP LTD. | $ACGL | Posner Brian S | Not found | P | Depositary Shares, Series G | 1000 | $17.34 | 5,000.0000 | 381,800,000 | 25.00% | 0.00% |
| May 7, 2025 | ARCH CAPITAL GROUP LTD. | $ACGL | Posner Brian S | Not found | A | Common Shares, $.0011 par value per share | 1564 | $0.00 | 120,104.0000 | 381,800,000 | 1.32% | 0.00% |
| May 9, 2024 | ARCH CAPITAL GROUP LTD. | $ACGL | Posner Brian S | Not found | A | Common Shares, $.0011 par value per share | 1455 | $0.00 | 118,540.0000 | 378,800,000 | 1.24% | 0.00% |
| May 4, 2023 | ARCH CAPITAL GROUP LTD. | $ACGL | Posner Brian S | Not found | A | Common Shares, $.0011 par value per share | 1714 | $0.00 | 117,085.0000 | 377,600,000 | 1.49% | 0.00% |
| June 7, 2022 | BIOGEN INC. | $BIIB | Posner Brian S | Director | G | Common Stock | 150 | $0.00 | 8,025.0000 | 170,800,000 | 1.83% | 0.00% |