Brian S Posner
Insider
First SEC filing: June 9, 2026 · Latest: June 9, 2026
Insider at
Insider transactions
7 buys (P)
3 sells (S)
Net: $130,250
Avg return of open purchases vs now: -11.8%
Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted
| Date | Ticker | Code | Shares | Price | Value | Owned after | Δ own | A/D | vs now |
|---|---|---|---|---|---|---|---|---|---|
| June 8, 2026 | DYN | P | 2,000 | $16.94 | $33,880 | 24,500 Direct | +8.89% | Acquired | -10.3% (price as of 2026-10-02) |
| June 5, 2026 | DYN | A | 35,152 | · | · | 35,152 Direct | · | Acquired | (price as of 2026-10-02) |
| June 3, 2026 | DYN | P | 2,500 | $17.48 | $43,700 | 22,500 Direct | +12.50% | Acquired | -13.0% (price as of 2026-10-02) |
| June 3, 2026 | ACGLO | S | 3,000 | $19.66 | $58,980 | 0 Direct | -100.00% | Disposed | -6.0% (price as of 2026-10-02) |
| May 26, 2026 | DYN | P | 2,000 | $18.21 | $36,420 | 20,000 Direct | +11.11% | Acquired | -16.5% (price as of 2026-10-02) |
| May 20, 2026 | DYN | P | 2,500 | $17.12 | $42,800 | 18,000 Direct | +16.13% | Acquired | -11.2% (price as of 2026-10-02) |
| May 11, 2026 | ACGLO | S | 2,000 | $17.14 | $34,280 | 0 Direct | -100.00% | Disposed | 7.8% (price as of 2026-10-02) |
| May 5, 2026 | ACGLO | A | 2,071 | · | · | 122,175 Direct | +1.72% | Acquired | (price as of 2026-10-02) |
| March 30, 2026 | DYN | P | 2,000 | $17.08 | $34,160 | 15,500 Direct | +14.81% | Acquired | -11.0% (price as of 2026-10-02) |
| March 11, 2026 | DYN | P | 2,000 | $19.35 | $38,700 | 13,500 Direct | +17.39% | Acquired | -21.4% (price as of 2026-10-02) |
| March 11, 2026 | ACGLO | S | 3,000 | $17.11 | $51,330 | 2,000 Direct | -60.00% | Disposed | 8.0% (price as of 2026-10-02) |
| March 6, 2026 | DYN | P | 3,000 | $15.06 | $45,180 | 11,500 Direct | +35.29% | Acquired | 0.9% (price as of 2026-10-02) |
| Oct. 1, 2025 | DYN | A | 70,000 | · | · | 70,000 Direct | · | Acquired | (price as of 2026-10-02) |
| Aug. 1, 2025 | ACGLO | P | 1,000 | $17.34 | $17,340 | 5,000 Direct | +25.00% | Acquired | 6.6% (price as of 2026-10-02) |
| May 7, 2025 | ACGLO | A | 1,564 | · | · | 120,104 Direct | +1.32% | Acquired | (price as of 2026-10-02) |
| May 9, 2024 | ACGLO | A | 1,455 | · | · | 118,540 Direct | +1.24% | Acquired | (price as of 2026-10-02) |
| May 4, 2023 | ACGLO | A | 1,714 | · | · | 117,085 Direct | +1.49% | Acquired | (price as of 2026-10-02) |
| Oct. 28, 2022 | ACGLO | P | 2,000 | $17.60 | $35,200 | 4,000 Direct | +100.00% | Acquired | 5.0% (price as of 2026-10-02) |
| May 4, 2022 | ACGLO | A | 2,642 | · | · | 115,371 Direct | +2.34% | Acquired | (price as of 2026-10-02) |
| May 4, 2022 | ACGLO | A | 2,642 | · | · | 112,729 Direct | +2.40% | Acquired | (price as of 2026-10-02) |
| April 29, 2022 | ACGLO | P | 2,000 | $19.23 | $38,460 | 2,000 Direct | · | Acquired | -3.9% (price as of 2026-10-02) |
| Sept. 30, 2021 | ACGLO | D | 2,000 | $25.00 | $50,000 | 0 Direct | -100.00% | Disposed | -26.1% (price as of 2026-10-02) |
| July 1, 2021 | BIIB | A | 775 | · | · | 8,175 Direct | +10.47% | Acquired | (price as of 2026-10-02) |
| June 14, 2021 | ACGLO | S | 4,000 | $25.24 | $100,960 | 2,000 Direct | -66.67% | Disposed | -26.8% (price as of 2026-10-02) |
| June 4, 2021 | BIIB | S 10b5-1 | 360 | $274.17 | $98,701 | 7,400 Direct | -4.64% | Disposed | -19.8% (price as of 2026-10-02) |
| May 6, 2021 | ACGLO | A | 3,143 | · | · | 110,087 Direct | +2.94% | Acquired | (price as of 2026-10-02) |
| May 6, 2021 | ACGLO | A | 3,143 | · | · | 106,944 Direct | +3.03% | Acquired | (price as of 2026-10-02) |
| June 3, 2020 | BIIB | A | 890 | · | · | 7,885 Direct | +12.72% | Acquired | (price as of 2026-10-02) |
| May 13, 2020 | ACGLO | P | 1,000 | $22.16 | $22,160 | 103,801 Direct | +0.97% | Acquired | -16.6% (price as of 2026-10-02) |
| May 7, 2020 | ACGLO | A | 5,058 | · | · | 102,801 Direct | +5.17% | Acquired | (price as of 2026-10-02) |
| May 7, 2020 | ACGLO | A | 5,058 | · | · | 97,743 Direct | +5.46% | Acquired | (price as of 2026-10-02) |
| May 6, 2020 | ACGLO | P | 1,000 | $23.72 | $23,720 | 92,685 Direct | +1.09% | Acquired | -22.1% (price as of 2026-10-02) |
| Dec. 2, 2019 | BIIB | S 10b5-1 | 1,055 | $292.35 | $308,429 | 6,995 Direct | -13.11% | Disposed | -24.8% (price as of 2026-10-02) |
| June 19, 2019 | BIIB | A | 1,155 | · | · | 8,050 Direct | +16.75% | Acquired | (price as of 2026-10-02) |
| May 8, 2019 | ACGLO | A | 2,832 | · | · | 91,685 Direct | +3.19% | Acquired | (price as of 2026-10-02) |
| May 8, 2019 | ACGLO | A | 3,726 | · | · | 88,853 Direct | +4.38% | Acquired | (price as of 2026-10-02) |
| Feb. 14, 2019 | BIIB | G | 315 | · | · | 6,895 Direct | -4.37% | Disposed | (price as of 2026-10-02) |
| Nov. 28, 2018 | ACGLO | P | 500 | $28.24 | $14,120 | 85,127 Direct | +0.59% | Acquired | -34.6% (price as of 2026-10-02) |
| Nov. 28, 2018 | ACGLO | P | 500 | $21.86 | $10,930 | 3,000 Direct | +20.00% | Acquired | -15.5% (price as of 2026-10-02) |
| Nov. 5, 2018 | ACGLO | P | 2,500 | $22.45 | $56,125 | 2,500 Direct | · | Acquired | -17.7% (price as of 2026-10-02) |
| June 12, 2018 | BIIB | A | 880 | · | · | 7,210 Direct | +13.90% | Acquired | (price as of 2026-10-02) |
| May 9, 2018 | ACGLO | A | 1,196 | · | · | 28,209 Direct | +4.43% | Acquired | (price as of 2026-10-02) |
| May 9, 2018 | ACGLO | A | 1,574 | · | · | 27,013 Direct | +6.19% | Acquired | (price as of 2026-10-02) |
| May 3, 2018 | ACGLO | P | 1,000 | $77.38 | $77,380 | 25,439 Direct | +4.09% | Acquired | -76.1% (price as of 2026-10-02) |
| May 3, 2018 | ACGLO | P | 2,000 | $79.25 | $158,500 | 24,439 Direct | +8.91% | Acquired | -76.7% (price as of 2026-10-02) |
| Jan. 2, 2018 | ACGLO | D | 2,146 | $25.00 | $53,650 | 0 Direct | -100.00% | Disposed | -26.1% (price as of 2026-10-02) |
| Sept. 25, 2017 | ACGLO | D | 695 | $25.00 | $17,375 | 2,146 Direct | -24.46% | Disposed | -26.1% (price as of 2026-10-02) |
| Sept. 18, 2017 | ACGLO | D | 4,659 | $25.00 | $116,475 | 2,841 Direct | -62.12% | Disposed | -26.1% (price as of 2026-10-02) |
| June 9, 2017 | BIIB | S 10b5-1 | 1,084 | $256.31 | $277,840 | 6,330 Direct | -14.62% | Disposed | -14.2% (price as of 2026-10-02) |
| June 7, 2017 | BIIB | A | 1,055 | · | · | 7,414 Direct | +16.59% | Acquired | (price as of 2026-10-02) |
| May 4, 2017 | ACGLO | A | 771 | · | · | 22,439 Direct | +3.56% | Acquired | (price as of 2026-10-02) |
| May 4, 2017 | ACGLO | A | 1,286 | · | · | 21,668 Direct | +6.31% | Acquired | (price as of 2026-10-02) |
| Nov. 18, 2016 | ACGLO | P | 6,000 | $21.88 | $131,280 | 6,000 Direct | · | Acquired | -15.5% (price as of 2026-10-02) |
| June 8, 2016 | BIIB | A | 1,060 | · | · | 6,335 Direct | +20.09% | Acquired | (price as of 2026-10-02) |
| May 6, 2016 | ACGLO | A | 1,066 | · | · | 20,382 Direct | +5.52% | Acquired | (price as of 2026-10-02) |
| May 6, 2016 | ACGLO | A | 1,777 | · | · | 19,316 Direct | +10.13% | Acquired | (price as of 2026-10-02) |
| June 22, 2015 | BIIB | S 10b5-1 | 470 | $415.00 | $195,050 | 5,275 Direct | -8.18% | Disposed | -47.0% (price as of 2026-10-02) |
| June 15, 2015 | BIIB | S 10b5-1 | 400 | $386.64 | $154,656 | 5,745 Direct | -6.51% | Disposed | -43.1% (price as of 2026-10-02) |
| June 10, 2015 | BIIB | A | 695 | · | · | 6,145 Direct | +12.75% | Acquired | (price as of 2026-10-02) |
| May 7, 2015 | ACGLO | A | 1,201 | · | · | 17,539 Direct | +7.35% | Acquired | (price as of 2026-10-02) |
| May 7, 2015 | ACGLO | A | 1,601 | · | · | 16,338 Direct | +10.86% | Acquired | (price as of 2026-10-02) |
| Feb. 6, 2015 | BIIB | G | 250 | · | · | 5,450 Direct | -4.39% | Disposed | (price as of 2026-10-02) |
| July 24, 2014 | BIIB | G | 300 | · | · | 5,700 Direct | -5.00% | Disposed | (price as of 2026-10-02) |
| June 20, 2014 | BIIB | S 10b5-1 | 605 | $315.00 | $190,575 | 6,000 Direct | -9.16% | Disposed | -30.2% (price as of 2026-10-02) |
| June 13, 2014 | BIIB | S 10b5-1 | 700 | $310.50 | $217,350 | 6,605 Direct | -9.58% | Disposed | -29.2% (price as of 2026-10-02) |
| June 12, 2014 | BIIB | A | 870 | · | · | 7,305 Direct | +13.52% | Acquired | (price as of 2026-10-02) |
| May 9, 2014 | ACGLO | A | 1,756 | · | · | 13,420 Direct | +15.05% | Acquired | (price as of 2026-10-02) |
| May 9, 2014 | ACGLO | A | 1,317 | · | · | 14,737 Direct | +9.81% | Acquired | (price as of 2026-10-02) |
| March 31, 2014 | BIIB | S 10b5-1 | 2,500 | $296.11 | $740,275 | 6,435 Direct | -27.98% | Disposed | -25.7% (price as of 2026-10-02) |
| March 31, 2014 | BIIB | S 10b5-1 | 500 | $300.00 | $150,000 | 8,935 Direct | -5.30% | Disposed | -26.7% (price as of 2026-10-02) |
| Aug. 19, 2013 | ACGLO | P | 2,500 | $23.58 | $58,950 | 7,500 Direct | +50.00% | Acquired | -21.6% (price as of 2026-10-02) |
| Aug. 2, 2013 | ACGLO | P | 5,000 | $25.25 | $126,250 | 5,000 Direct | · | Acquired | -26.8% (price as of 2026-10-02) |
| June 12, 2013 | BIIB | A | 1,305 | · | · | 9,435 Direct | +16.05% | Acquired | (price as of 2026-10-02) |
| June 11, 2013 | BIIB | S 10b5-1 | 2,020 | $219.62 | $443,632 | 8,130 Direct | -19.90% | Disposed | 0.1% (price as of 2026-10-02) |
| May 9, 2013 | ACGLO | A | 1,401 | · | · | 11,664 Direct | +13.65% | Acquired | (price as of 2026-10-02) |
| May 9, 2013 | ACGLO | A | 1,401 | · | · | 10,263 Direct | +15.81% | Acquired | (price as of 2026-10-02) |
| March 18, 2013 | BIIB | S 10b5-1 | 4,500 | $174.81 | $786,645 | 10,150 Direct | -30.72% | Disposed | 25.8% (price as of 2026-10-02) |
| June 8, 2012 | BIIB | A | 2,020 | · | · | 14,650 Direct | +15.99% | Acquired | (price as of 2026-10-02) |
| June 7, 2012 | BIIB | S 10b5-1 | 2,500 | $135.00 | $337,500 | 12,630 Direct | -16.52% | Disposed | 62.9% (price as of 2026-10-02) |
| June 7, 2012 | BIIB | M 10b5-1 | 2,500 | · | · | 0 Direct | -100.00% | Disposed | (price as of 2026-10-02) |
| June 7, 2012 | BIIB | M 10b5-1 | 2,500 | $71.38 | $178,450 | 15,130 Direct | +19.79% | Acquired | 208.0% (price as of 2026-10-02) |
| June 4, 2012 | BIIB | M 10b5-1 | 2,400 | · | · | 2,500 Direct | -48.98% | Disposed | (price as of 2026-10-02) |
| June 4, 2012 | BIIB | S 10b5-1 | 2,400 | $126.45 | $303,480 | 12,630 Direct | -15.97% | Disposed | 73.9% (price as of 2026-10-02) |
| June 4, 2012 | BIIB | M 10b5-1 | 2,400 | $71.38 | $171,312 | 15,030 Direct | +19.00% | Acquired | 208.0% (price as of 2026-10-02) |
| May 9, 2012 | ACGLO | A | 1,944 | · | · | 8,862 Direct | +28.10% | Acquired | (price as of 2026-10-02) |
| May 9, 2012 | ACGLO | A | 1,944 | · | · | 6,918 Direct | +39.08% | Acquired | (price as of 2026-10-02) |
| Nov. 4, 2011 | ACGLO | A | 332 | · | · | 332 Direct | · | Acquired | (price as of 2026-10-02) |
| Aug. 29, 2011 | BIIB | M 10b5-1 | 15,000 | · | · | 0 Direct | -100.00% | Disposed | (price as of 2026-10-02) |
| Aug. 29, 2011 | BIIB | S 10b5-1 | 15,000 | $92.53 | $1,387,950 | 12,630 Direct | -54.29% | Disposed | 137.6% (price as of 2026-10-02) |
| Aug. 29, 2011 | BIIB | M 10b5-1 | 15,000 | $71.38 | $1,070,700 | 27,630 Direct | +118.76% | Acquired | 208.0% (price as of 2026-10-02) |
| June 1, 2011 | BIIB | A | 2,900 | · | · | 12,630 Direct | +29.80% | Acquired | (price as of 2026-10-02) |
| May 25, 2011 | BIIB | M 10b5-1 | 20,000 | · | · | 15,000 Direct | -57.14% | Disposed | (price as of 2026-10-02) |
| May 25, 2011 | BIIB | M 10b5-1 | 5,975 | · | · | 0 Direct | -100.00% | Disposed | (price as of 2026-10-02) |
| May 25, 2011 | BIIB | S 10b5-1 | 13,170 | $94.43 | $1,243,643 | 9,730 Direct | -57.51% | Disposed | 132.8% (price as of 2026-10-02) |
| May 25, 2011 | BIIB | S 10b5-1 | 12,805 | $93.74 | $1,200,341 | 22,900 Direct | -35.86% | Disposed | 134.6% (price as of 2026-10-02) |
| May 25, 2011 | BIIB | M 10b5-1 | 20,000 | $71.38 | $1,427,600 | 35,705 Direct | +127.35% | Acquired | 208.0% (price as of 2026-10-02) |
| May 25, 2011 | BIIB | M 10b5-1 | 5,975 | $53.43 | $319,244 | 15,705 Direct | +61.41% | Acquired | 311.5% (price as of 2026-10-02) |
| May 6, 2011 | ACGLO | A | 589 | · | · | 1,658 Direct | +55.10% | Acquired | (price as of 2026-10-02) |
| May 6, 2011 | ACGLO | A | 737 | · | · | 1,069 Direct | +221.99% | Acquired | (price as of 2026-10-02) |
| June 9, 2010 | BIIB | A | 5,735 | · | · | 9,730 Direct | +143.55% | Acquired | (price as of 2026-10-02) |
Showing latest 100 of 106 transactions
P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding
Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.
Derivative holdings (Form 4 Table II) Options, RSUs and convertible securities reported on Form 4 Table II.
| Date | Ticker | Security | Underlying | Exercise price | Expiration | Shares | A/D |
|---|---|---|---|---|---|---|---|
| June 5, 2026 | DYN | Stock option (right to buy) | Common Stock | $17.04 | June 4, 2036 | 35,152 | Acquired |
| Oct. 1, 2025 | DYN | Stock option (right to buy) | Common Stock | $12.50 | Sept. 30, 2035 | 70,000 | Acquired |
| June 7, 2012 | BIIB | Stock Option (Right to Buy) | Common Stock | $71.38 | July 22, 2018 | 2,500 | Disposed |
| June 4, 2012 | BIIB | Stock Option (Right to Buy) | Common Stock | $71.38 | July 22, 2018 | 2,400 | Disposed |
| Aug. 29, 2011 | BIIB | Stock Option (Right to Buy) | Common Stock | $71.38 | July 22, 2018 | 15,000 | Disposed |
| May 25, 2011 | BIIB | Stock Option (Right to Buy) | Common Stock | $71.38 | July 22, 2018 | 20,000 | Disposed |
| May 25, 2011 | BIIB | Stock Option (Right to Buy) [F5] | Common Stock | $53.43 | June 2, 2019 | 5,975 | Disposed |
| June 3, 2009 | BIIB | Stock Option (Right to Buy) [F1] | Common Stock | $53.43 | June 2, 2019 | 5,975 | Acquired |
| July 23, 2008 | BIIB | Stock Option (right to buy) | Common Stock | $71.38 | July 22, 2018 | 35,000 | Acquired |
| July 23, 2008 | BIIB | Stock Option (right to buy) | Common Stock | $71.38 | July 22, 2018 | 4,900 | Acquired |
Exercise/conversion price is blank when not applicable (e.g. RSUs).
Initial ownership (Form 3) 3 holdings
Securities held when first becoming an insider, per SEC Form 3.