Brian S Posner

CIK 1372455 · last filed 2026-06-09

Brian S Posner is a corporate insider who has filed 80 SEC Form 4 insider transactions across 9 companies since 2008. The most recent filing, for DYN, was dated Jun 9, 2026. Across all open-market trades the lifetime net is −$5.7M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $2.1M across reported positions.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

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Disclosed Exposure

$2.08M

Companies

9

Total Filings

80

Lifetime Open-Market Net

-$5.72M

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
DYN Director 24,500 $18.19 $445.7K $274.8K 8 2026-06-09
ACGLO Director 0 $19.33 $0 $208.3K 21 2026-06-04
BIIB Director 8,175 $200.05 $1.64M -$6.74M 26 2021-07-02
Bioverativ Inc. (BIVV) Delisted Director 0 $166.9K 7 2018-03-08
ARCH CAPITAL GROUP LTD. (ARHpC.CL) Delisted Director 6,000 $0 1 2018-01-02
ARCH CAPITAL GROUP LTD. (ARHpC) Delisted Director 6,000 $316.4K 10 2017-09-26
BG Medicine, Inc. (BGMD) Delisted Director 20,000 $52.0K 4 2013-06-14
ANADYS PHARMACEUTICALS INC (ANDS) Delisted Director $0 1 2011-08-24
ARCH CAPITAL GROUP LTD. (ARHpB) Delisted Director 1,658 $0 2 2011-05-09

Recent Filings

80 filings
Form 4 transactions across all companies, newest first.
Filed Symbol Action Net Shares Net $ Link
2026-06-09 DYN Mixed +2,000 $33.9K EDGAR
2026-06-05 DYN Buy (P) +2,500 $43.7K EDGAR
2026-06-04 ACGLO Sell (S) −3,000 -$59.0K EDGAR
2026-05-28 DYN Buy (P) +2,000 $36.4K EDGAR
2026-05-22 DYN Buy (P) +2,500 $42.8K EDGAR
2026-05-12 ACGLO Sell (S) −2,000 -$34.3K EDGAR
2026-05-07 ACGLO Grant (A) +2,071 $0 EDGAR
2026-04-01 DYN Buy (P) +2,000 $34.2K EDGAR
2026-03-13 DYN Buy (P) +2,000 $38.7K EDGAR
2026-03-12 ACGLO Sell (S) −3,000 -$51.3K EDGAR
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Codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.