Brian S Posner

CIK 1372455 · last filed 2026-06-09

"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

$4.23M

Companies

7

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 $25.90 $634.5K $274.8K 8 2026-06-09
ACGLO Director 0 $19.50 $0 $208.3K 21 2026-06-04
BIIB Director 8,175 $205.61 $1.68M -$6.74M 26 2021-07-02
Bioverativ Inc. (BIVV) Delisted Director 0 $166.9K 7 2018-03-08
ACGL Director 18,000 $106.48 $1.92M $316.4K 13 2018-01-02
BG Medicine, Inc. (BGMD) Delisted Director 5,000 $52.0K 4 2013-06-14
ANADYS PHARMACEUTICALS INC (ANDS) Delisted Director $0 1 2011-08-24

Recent Filings · Page 5 of 8

80 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2017-09-19 ACGL Disp (D) −4,659 -$116.5K EDGAR
2017-08-10 Bioverativ Inc. (BIVV) Delisted Buy (P) +1,000 $59.2K EDGAR
2017-06-12 BIIB Sell (S) −1,084 -$277.8K EDGAR
2017-06-09 BIIB Grant (A) +1,055 $0 EDGAR
2017-05-24 Bioverativ Inc. (BIVV) Delisted Buy (P) +2,000 $107.7K EDGAR
2017-05-05 ACGL Grant (A) +2,057 $0 EDGAR
2017-04-17 Bioverativ Inc. (BIVV) Delisted Grant (A) +1,056 $60.0K EDGAR
2017-03-27 Bioverativ Inc. (BIVV) Delisted Grant (A) $0 EDGAR
2017-02-16 Bioverativ Inc. (BIVV) Delisted Grant (A) $0 EDGAR
2016-11-21 ACGL Buy (P) +6,000 $131.3K EDGAR
Showing 4150 of 80
Page 5 of 8
Form 4 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.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.