Michael Martin Breen

CIK 1863633 · CEO and Director · last filed 2025-09-08

Michael Martin Breen is a CEO and Director who has filed 7 SEC Form 4 insider transactions across 1 company since 2021. The most recent filing, for GTBP, was dated Sep 8, 2025. Across all open-market trades the lifetime net is +$25.0K, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $9.0K 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

$9.0K

Companies

1

Total Filings

7

Lifetime Open-Market Net

$25.0K

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
GTBP	CEO and Director	28,541	$0.32	$9.0K	$25.0K	6	2025-09-08

Recent Filings

7 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
2025-09-08	GTBP	Grant (A)	—	$0	EDGAR
2023-08-15	GTBP	Grant (A)	+200,000	$57.4K	EDGAR
2023-05-05	—	Mixed	+1,134,683	$138.1K
2023-04-11	GTBP	Buy (P)	+50,000	$25.0K	EDGAR
2023-02-01	GTBP	Grant (A)	—	$0	EDGAR
2022-07-19	GTBP	Grant (A)	+278,058	$0	EDGAR
2021-11-12	GTBP	Mixed	+328,160	$170.3K	EDGAR

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.