Acumen Pharmaceuticals ABOS Insider Ownership

NASDAQ ABOS

$2.06 +0.04 (+2.16%)

As of: Oct 21, 2026 · 1:12 PM EDT

Insider Holdings by Owner

2.67Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026

Insider Ownership

3.49%

▼-0.182% pp QoQ

Shares Held by Insiders

2.52Mn

filed for Sep 2026

▼-4.96% QoQ

Shares Outstanding

72.31Mn

72,314,714 shares

Direct Holdings

2.52Mn

Indirect: 0

Net Shares Traded (QoQ)

-131.60K

net selling in Sep 2026

Insiders Holding Shares

with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold

Latest quarter —

Net over range —

Buying quarters —

Insider Ownership Summary

Updated Oct 10, 2026

Across the past 12 months, open-market trades by Acumen Pharmaceuticals insiders were all sales, totaling $625,431 (305.13K shares).

Behind Acumen Pharmaceuticals' open-market sales in the past 12 months were 9 insiders, and no insider bought.
Derek M. Meisner (Chief Legal Officer & Corporate Secretary) led open-market sales of Acumen Pharmaceuticals stock over the past 12 months with $248,888 (115.51K shares), most recently on March 6, 2026.
Derrell Porter (Director) made the most recent open-market trade by an insider of Acumen Pharmaceuticals, a sale of 13.04K shares for $30,318 on June 17, 2026.
Away from the open market, ABOS insiders received 6.78Mn shares in stock awards and acquired 48.75K shares through option exercises and conversions over the last 12 months.
Per Business Quant data, Acumen Pharmaceuticals insiders hold 2.52Mn shares in total based on their latest Form 4 filings, down 4.96% from 2.65Mn shares at the end of Q2 2026.
Acumen Pharmaceuticals insiders report no indirect holdings: all 2.52Mn shares are held directly.
Per Business Quant, 12 insiders of ABOS hold shares, counting officers, directors and 10% owners who have filed a Form 4 in the past two years.
ABOS's three largest insider shareholders, per their latest Form 4 filings, are Daniel Joseph Oconnell (Chief Executive Officer, 881.27K shares), Matt Zuga (CFO & Chief Business Officer, 304.92K shares) and Eric Siemers (Chief Medical Officer, 255.37K shares).
Daniel Joseph Oconnell holds 34.94% of the combined insider position in Acumen Pharmaceuticals.
Institutional holders reported 66.18% of Acumen Pharmaceuticals' outstanding shares for Q2 2026; insiders' latest Form 4 filings put their stake at about 3.49%, and other investors, including the public, hold the remaining 30.33%.
Over the trailing 12 months, 15 insiders reported transactions in ABOS stock across 38 Form 4 filings.
Insider figures for ABOS include Form 4 filings through June 17, 2026.

Form 4 Holdings

Insiders Holding ABOS

Insiders 15

Shares held 2.67Mn

Of outstanding 3.69%

#	Insider	Position	Direct	Indirect	Total	Share of Insiders	Last Filed
1	Daniel Joseph Oconnell	Chief Executive Officer	881,275	0	881,275	33.0%	23 Jan, 2026
2	Matt Zuga	Cfo Chief Business Officer	304,924	0	304,924	11.4%	23 Jan, 2026
3	Eric Siemers	Chief Medical Officer	255,371	0	255,371	9.6%	23 Jan, 2026
4	James J. Doherty	President And Cdo	220,900	0	220,900	8.3%	21 Jan, 2026
5	John A Iii Stalfort	Director	220,624	0	220,624	8.3%	05 Jun, 2026
6	Russell Barton	Chief Operating Officer	205,092	0	205,092	7.7%	23 Jan, 2026
7	Derek M Meisner	Chief Legal Officer Corp Sec	173,999	0	173,999	6.5%	10 Mar, 2026
8	Amy Schacterle	Chief Regulatory Officer	92,303	0	92,303	3.5%	21 Jan, 2026
9	Capital Management, L.P. Ra	Director, TenPercentOwner	0	48,300	48,300	1.8%	05 Jun, 2026
10	Kimberlee C Drapkin	Director	48,300	0	48,300	1.8%	05 Jun, 2026
11	Jeffrey L. Ives	Director	48,300	0	48,300	1.8%	05 Jun, 2026
12	Laura Stoppel	Director	48,300	0	48,300	1.8%	05 Jun, 2026
13	Nathan B Fountain	Director	48,150	0	48,150	1.8%	10 Jun, 2026
14	George Golumbeski	Director	35,500	0	35,500	1.3%	05 Jun, 2026
15	Derrell Porter	Director	35,500	0	35,500	1.3%	17 Jun, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

246 Insider Transactions

Source SEC Form 4

Latest quarter Sep 2026

Date	Insider	Position	Transaction	Shares	Price	Value	Shares Held After	Ownership
15 Jun, 2026	Derrell Porter	Director	Acquired M	6,460	$1.07	$6.91K	54,760	Direct
15 Jun, 2026	Derrell Porter	Director	Disposed S	6,460	$2.35	$15.15K	48,300	Direct
16 Jun, 2026	Derrell Porter	Director	Disposed S	12,800	$2.33	$29.77K	35,500	Direct
17 Jun, 2026	Derrell Porter	Director	Acquired M	13,040	$1.07	$13.95K	48,540	Direct
17 Jun, 2026	Derrell Porter	Director	Disposed S	13,040	$2.33	$30.32K	35,500	Direct
15 Jun, 2026	Derrell Porter	Director	Disposed M	6,460	$0.00	$0	13,040	Direct
17 Jun, 2026	Derrell Porter	Director	Disposed M	13,040	$0.00	$0	0	Direct
09 Jun, 2026	Nathan B Fountain	Director	Disposed S	6,400	$2.23	$14.27K	48,150	Direct
03 Jun, 2026	Laura Stoppel	Director	Acquired A	35,500	$0.00	$0	48,300	Direct
03 Jun, 2026	John A Iii Stalfort	Director	Acquired A	35,500	$0.00	$0	220,624	Direct
03 Jun, 2026	Capital Management, L.P. Ra	Director, TenPercentOwner	Acquired A	35,500	$0.00	$0	48,300	Indirect
03 Jun, 2026	Nathan B Fountain	Director	Acquired A	35,500	$0.00	$0	54,550	Direct
03 Jun, 2026	George Golumbeski	Director	Acquired A	35,500	$0.00	$0	35,500	Direct
03 Jun, 2026	Kimberlee C Drapkin	Director	Acquired A	35,500	$0.00	$0	48,300	Direct
03 Jun, 2026	Jeffrey L. Ives	Director	Acquired A	35,500	$0.00	$0	48,300	Direct
03 Jun, 2026	Derrell Porter	Director	Acquired A	35,500	$0.00	$0	48,300	Direct
03 Jun, 2026	George Golumbeski	Director	Acquired A	53,250	$0.00	$0	53,250	Direct
03 Jun, 2026	Laura Stoppel	Director	Acquired A	53,250	$0.00	$0	53,250	Direct
03 Jun, 2026	Derrell Porter	Director	Acquired A	53,250	$0.00	$0	53,250	Direct
03 Jun, 2026	Kimberlee C Drapkin	Director	Acquired A	53,250	$0.00	$0	53,250	Direct

Showing 1 to 20 of 246 transactions