Posner Brian S Insider Trading Activity (DYN)

Summary

Updated Jul 16, 2026

Posner Brian S has filed 7 SEC Form 4 filings across 2 companies in the last 90 days — active on both sides. Lifetime open-market purchases: $292K. Lifetime open-market sales: $145K. Historical track record: 3/5 stars across 4 tracked purchases.

Role	Insider
Notability	20/100

Track Record

InsiderAlpha computes a forward-return-based score for every insider with enough Form 4 purchase history. The metrics below reflect realised performance after each tracked open-market purchase.

InsiderAlpha rating	★★★☆☆ (3/5)
Total purchases tracked	4
Purchases with forward-return data	4
30-day win rate	7500%
90-day win rate	5000%
Avg 5-day return	+864.76%
Avg 30-day return	+564.44%
Avg 90-day return	+909.73%
Best 30-day return	+2348.59%

Recent Transactions

Date	Ticker	Company	Code	Shares	Price	Value
2026-06-09	DYN	Dyne Therapeutics, Inc.	P — Open-market purchase	2.0K	$16.94	$34K
2026-06-05	DYN	Dyne Therapeutics, Inc.	P — Open-market purchase	2.5K	$17.48	$44K
2026-06-04	ACGL	ARCH CAPITAL GROUP LTD.	S — Open-market sale	3.0K	$19.66	$59K
2026-05-28	DYN	Dyne Therapeutics, Inc.	P — Open-market purchase	2.0K	$18.21	$36K
2026-05-22	DYN	Dyne Therapeutics, Inc.	P — Open-market purchase	2.5K	$17.12	$43K
2026-05-12	ACGL	ARCH CAPITAL GROUP LTD.	S — Open-market sale	2.0K	$17.14	$34K
2026-05-07	ACGL	ARCH CAPITAL GROUP LTD.	A — Grant or award	2.1K	—
2026-04-01	DYN	Dyne Therapeutics, Inc.	P — Open-market purchase	2.0K	$17.08	$34K
2026-03-13	DYN	Dyne Therapeutics, Inc.	P — Open-market purchase	2.0K	$19.35	$39K
2026-03-12	ACGL	ARCH CAPITAL GROUP LTD.	S — Open-market sale	3.0K	$17.11	$51K
2026-03-10	DYN	Dyne Therapeutics, Inc.	P — Open-market purchase	3.0K	$15.06	$45K
2025-08-01	ACGL	ARCH CAPITAL GROUP LTD.	P — Open-market purchase	1.0K	$17.34	$17K

Frequently Asked Questions

Who is Posner Brian S?

Posner Brian S is a corporate insider — currently tracked as Insider of Dyne Therapeutics, Inc. (DYN). InsiderAlpha tracks every SEC Form 4 filing in real time.

How many SEC Form 4 filings has Posner Brian S submitted recently?

7 primary Form 4 filings in the last 90 days, covering 2 companies.

Has Posner Brian S been buying or selling stock?

Recorded transactions: 8 open-market purchases ($292K) and 3 open-market sales ($145K) across all tracked filings.

How accurate is Posner Brian S's historical track record?

Across 4 tracked purchases, Posner Brian S averaged +564.4% avg 30-day return with a 7500% 30-day win rate. InsiderAlpha rates the track record at 3/5 stars.

Where can I see all of Posner Brian S's SEC filings?

All Form 4 filings, transaction values, and 10b5-1 plan flags are listed on this page and updated in real time as new SEC EDGAR filings are processed.

Posner Brian S — SEC Form 4 Insider Trading Activity

Summary

Profile

Board memberships