John Cox

CIK 1498428 · CEO & President · last filed 2026-09-08

"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
$14.54M
Companies
5
Total Filings
84
Lifetime Open-Market Net
-$13.35M

Charts

Trading activity, where the exposure sits, and each trade against the stock price.

Filer Profile

Reported Address
C/O BIOVERATIV INC.
225 SECOND AVENUE
WALTHAM, MA 02451
Related Filers
BIOGEN INC. — 37 joint filings, latest 2016-04-05
Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

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 CEO & President 375,507 $15.29 $5.74M $1.39M 15 2026-09-08
Sigilon Therapeutics, Inc. (SGTX) Delisted Director 342 $22.47 $7.7K $0 5 2023-08-11
RGEN Director 923 $184.76 $170.5K -$4.07M 10 2020-03-26
Bioverativ Inc. (BIVV) Delisted Chief Executive Officer 0 — — $0 9 2018-03-08
BIIB EVP Pharmaceutical Oper & Tech 39,045 $220.94 $8.63M -$10.66M 36 2016-04-05

Recent Filings · Page 7 of 9

84 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
2013-11-19 RGEN Grant (A) — $0 EDGAR
2013-05-07 BIIB Tax (F) −866 -$189.5K EDGAR
2013-02-26 BIIB Mixed +1,371 -$201.7K EDGAR
2013-02-14 BIIB Grant (A) — $0 EDGAR
2013-02-12 BIIB Mixed +5,210 -$488.2K EDGAR
2012-05-04 BIIB Tax (F) −765 -$102.7K EDGAR
2012-02-27 BIIB Mixed −63 -$310.3K EDGAR
2012-02-13 BIIB Mixed +3,188 -$177.1K EDGAR
2012-02-10 BIIB Grant (A) — $0 EDGAR
2011-11-03 BIIB Mixed — -$90.3K EDGAR
Showing 61–70 of 84
Page 7 of 9
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.