Insider · CIK 0001372455
Brian S Posner
Files at: DYN, ACGL, BIIB, BIVV. On EDGAR ↗
Reported trades — common stock
| Trade | Reported (ET) | Company | Shares | Avg price | Total | Owned after | Δ stake | Flags |
|---|---|---|---|---|---|---|---|---|
| Jun 8, 2026 PForm 4 → | Jun 9, 5:06 pm EDT | Dyne Therapeutics, Inc.DYN | 2,000 | $16.94 | $33,880 | 24,500 | +8.89% | |
| Jun 3, 2026 PForm 4 → | Jun 5, 4:10 pm EDT | Dyne Therapeutics, Inc.DYN | 2,500 | $17.48 | $43,700 | 22,500 | +12.5% | |
| Jun 3, 2026 SForm 4 → | Jun 4, 6:23 pm EDT | ARCH CAPITAL GROUP LTD.ACGL | 3,000 | $19.66 | $58,980 | 0 | −100% | |
| Feb 14, 2019 GForm 4 → | Feb 15, 4:21 pm EST | BIOGEN INC.BIIB | 315 | — | — | 6,895 | — | plan? |
| Nov 28, 2018 PForm 4 → | Nov 29, 4:52 pm EST | ARCH CAPITAL GROUP LTD.ACGL | 1,000 | $25.05 | $25,051 | 85,127 | +1.19% | plan? |
| Nov 5, 2018 PForm 4 → | Nov 6, 3:00 pm EST | ARCH CAPITAL GROUP LTD.ACGL | 2,500 | $22.45 | $56,124 | 2,500 | — | plan? |
| Jun 12, 2018 AForm 4 → | Jun 14, 5:35 pm EDT | BIOGEN INC.BIIB | 880 | — | — | 7,210 | — | plan? |
| May 9, 2018 AForm 4 → | May 10, 1:42 pm EDT | ARCH CAPITAL GROUP LTD.ACGL | 2,770 | — | — | 28,209 | — | plan? |
| May 3, 2018 PForm 4 → | May 4, 4:05 pm EDT | ARCH CAPITAL GROUP LTD.ACGL | 3,000 | $78.63 | $235,876 | 25,439 | +13.4% | plan? |
| Mar 8, 2018 DForm 4 → | Mar 8, 12:49 pm EST | Bioverativ Inc.BIVV | 6,693 | — | — | 0 | — | plan? |
| Jan 2, 2018 DForm 4 → | Jan 2, 5:26 pm EST | ARCH CAPITAL GROUP LTD.ACGL | 2,146 | $25.00 | $53,650 | 0 | — | plan? |
| Sep 25, 2017 DForm 4 → | Sep 26, 11:07 am EDT | ARCH CAPITAL GROUP LTD.ACGL | 695 | $25.00 | $17,375 | 2,146 | — | plan? |
| Sep 18, 2017 DForm 4 → | Sep 19, 5:08 pm EDT | ARCH CAPITAL GROUP LTD.ACGL | 4,659 | $25.00 | $116,475 | 2,841 | — | plan? |
| Aug 9, 2017 PForm 4 → | Aug 10, 4:50 pm EDT | Bioverativ Inc.BIVV | 1,000 | $59.19 | $59,190 | 6,693 | +17.6% | plan? |
| Jun 9, 2017 SForm 4 → | Jun 12, 4:29 pm EDT | BIOGEN INC.BIIB | 1,084 | $256.31 | $277,840 | 6,330 | −14.6% | plan? |
| Jun 7, 2017 AForm 4 → | Jun 9, 5:48 pm EDT | BIOGEN INC.BIIB | 1,055 | — | — | 7,414 | — | plan? |
| May 24, 2017 PForm 4 → | May 24, 5:03 pm EDT | Bioverativ Inc.BIVV | 2,000 | $53.86 | $107,724 | 5,693 | +54.2% | plan? |
| May 4, 2017 AForm 4 → | May 5, 4:55 pm EDT | ARCH CAPITAL GROUP LTD.ACGL | 2,057 | — | — | 22,439 | — | plan? |
| Apr 17, 2017 AForm 4 → | Apr 17, 4:06 pm EDT | Bioverativ Inc.BIVV | 1,056 | $56.83 | $60,012 | 3,693 | — | plan? |
| Nov 18, 2016 PForm 4 → | Nov 21, 4:05 pm EST | ARCH CAPITAL GROUP LTD.ACGL | 6,000 | $21.88 | $131,271 | 6,000 | — | plan? |
| Jun 8, 2016 AForm 4 → | Jun 9, 4:33 pm EDT | BIOGEN INC.BIIB | 1,060 | — | — | 6,335 | — | plan? |
| May 6, 2016 AForm 4 → | May 9, 2:04 pm EDT | ARCH CAPITAL GROUP LTD.ACGL | 2,843 | — | — | 20,382 | — | plan? |
| Jun 22, 2015 SForm 4 → | Jun 23, 4:14 pm EDT | BIOGEN INC.BIIB | 470 | $415.00 | $195,050 | 5,275 | −8.18% | plan? |
| Jun 15, 2015 SForm 4 → | Jun 16, 6:54 pm EDT | BIOGEN INC.BIIB | 400 | $386.64 | $154,656 | 5,745 | −6.51% | plan? |
| Jun 10, 2015 AForm 4 → | Jun 11, 4:32 pm EDT | BIOGEN INC.BIIB | 695 | — | — | 6,145 | — | plan? |
| May 7, 2015 AForm 4 → | May 11, 11:32 am EDT | ARCH CAPITAL GROUP LTD.ACGL | 2,802 | — | — | 17,539 | — | plan? |
| Feb 6, 2015 GForm 4 → | Feb 10, 5:04 pm EST | BIOGEN IDEC INC.BIIB | 250 | — | — | 5,450 | — | plan? |
Reported trades — derivatives (options, RSUs, warrants)
| Trade | Reported (ET) | Company | Shares | Avg price | Total | Owned after | Δ stake | Flags |
|---|---|---|---|---|---|---|---|---|
| Jun 5, 2026 AForm 4 → | Jun 9, 5:06 pm EDT | Dyne Therapeutics, Inc.DYN | 35,152 | — | — | 35,152 | — | |
| Mar 8, 2018 DForm 4 → | Mar 8, 12:49 pm EST | Bioverativ Inc.BIVV | 36,162 | — | — | 0 | — | |
| Jan 31, 2018 AForm 4 → | Feb 2, 5:15 pm EST | Bioverativ Inc.BIVV | 6,364 | — | — | 6,364 | — | |
| Feb 14, 2017 AForm 4/A → | Mar 27, 4:12 pm EDT | Bioverativ Inc.BIVV | 29,798 | — | — | 2,980 | — | |
| Feb 14, 2017 AForm 4 → | Feb 16, 4:44 pm EST | Bioverativ Inc.BIVV | 29,744 | — | — | 2,974 | — | amended |