Catherine Stehman-Breen

CIK 1702233 · SVP, Chief Medical Officer · last filed 2026-06-09

Catherine Stehman-Breen is a SVP, Chief Medical Officer who has filed 22 SEC Form 4 insider transactions across 4 companies since 2017. The most recent filing, for DYN, was dated Jun 9, 2026. Current disclosed insider exposure totals $1.8M 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.

Disclosed Exposure

$1.78M

Companies

Total Filings

Lifetime Open-Market Net

Charts

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

Filer Profile

Reported Address

C/O GENERATION BIO CO.
301 BINNEY STREET
CAMBRIDGE, MA 02142

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	Director	115,713	$15.35	$1.78M	$0	8	2026-06-09
TNYA	Director	—	$0.56	—	$0	5	2026-05-29
Generation Bio Co. (GBIO) Delisted	Director	0	$5.34	$0	$0	8	2026-02-09
SRPT	SVP, Chief Medical Officer	—	$17.21	—	$0	1	2017-04-05

Recent Filings

22 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
2026-06-09	DYN	Grant (A)	—	$0	EDGAR
2026-05-29	TNYA	Grant (A)	—	$0	EDGAR
2026-02-09	Generation Bio Co. (GBIO) Delisted	Mixed	−4,752	$0	EDGAR
2025-06-06	Generation Bio Co. (GBIO) Delisted	Grant (A)	—	$0	EDGAR
2025-06-03	DYN	Grant (A)	—	$0	EDGAR
2025-05-30	TNYA	Grant (A)	—	$0	EDGAR
2024-10-21	TNYA	Grant (A)	—	$0	EDGAR
2024-06-10	Generation Bio Co. (GBIO) Delisted	Grant (A)	—	$0	EDGAR
2024-05-24	DYN	Grant (A)	—	$0	EDGAR
2023-06-12	TNYA	Grant (A)	—	$0	EDGAR

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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.