ABOS Acumen Pharmaceuticals, Inc.

NASDAQ
$2.57

Acumen Pharmaceuticals, Inc. (ABOS) Institutional Ownership

What the institutions did with ABOS last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.

Managers compared
113
filed both this quarter and last
Managers holding
96
+13 on the quarter
Buyers
51
30 opened new
Sellers
32
17 sold out entirely
Buyer share
61.5%
of managers who traded it
Breadth
+22.9
net buyers, as a share of those trading

Every manager below opens. Subscribers can see any firm's whole portfolio — every position, its weight, and what they bought, trimmed and exited last quarter.

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Ownership map

Each block is one manager, sized by shares held and colored by how much they moved the position last quarter. Green added, red cut, grey stood pat.

Cut Unchanged Added Color saturates at ±50%.

Largest holders

Manager Shares % of reported
RA CAPITAL MANAGEMENT, L.P. 21.0M 43.9%
Sands Capital Alternatives, LLC 3.7M 7.8%
BlackRock, Inc. 2.5M 5.2%
Alyeska Investment Group, L.P. 2.5M 5.1%
FRANKLIN RESOURCES INC 2.3M 4.8%
ADAR1 Capital Management, LLC 2.1M 4.4%
VANGUARD CAPITAL MANAGEMENT LLC 1.7M 3.5%
Knollwood Investment Advisory, LLC 1.6M 3.4%
GEODE CAPITAL MANAGEMENT, LLC 1.1M 2.4%
Ikarian Capital, LLC 1.1M 2.2%
Hudson Bay Capital Management LP 955.0K 2.0%
Pathstone Holdings, LLC 859.1K 1.8%
RENAISSANCE TECHNOLOGIES LLC 675.0K 1.4%
TWO SIGMA INVESTMENTS, LP 622.9K 1.3%
STATE STREET CORP 600.5K 1.3%
NORTHERN TRUST CORP 360.7K 0.8%
VANGUARD PORTFOLIO MANAGEMENT LLC 320.8K 0.7%
DIMENSIONAL FUND ADVISORS LP 291.6K 0.6%
VANGUARD FIDUCIARY TRUST CO 291.2K 0.6%
BANK OF AMERICA CORP /DE/ 274.8K 0.6%
BOOTHBAY FUND MANAGEMENT, LLC 273.0K 0.6%
ACADIAN ASSET MANAGEMENT LLC 270.3K 0.6%
NOMURA HOLDINGS INC 189.7K 0.4%
GOLDMAN SACHS GROUP INC 183.9K 0.4%
BRIDGEWAY CAPITAL MANAGEMENT, LLC 176.2K 0.4%

Largest changes

Manager Action Previous Current Change
BlackRock, Inc. Increased 178.3K 2.5M +2.3M
FMR LLC Reduced 1.2M 7.5K -1.1M
GEODE CAPITAL MANAGEMENT, LLC Increased 416.2K 1.1M +725.6K
SG Americas Securities, LLC Sold Out 719.3K 0 -719.3K
MILLENNIUM MANAGEMENT LLC Reduced 659.7K 60.6K -599.1K
Laurion Capital Management LP Sold Out 525.4K 0 -525.4K
SUSQUEHANNA INTERNATIONAL GROUP, LLP Reduced 601.5K 126.1K -475.4K
STATE STREET CORP Increased 151.7K 600.5K +448.8K
VANGUARD PORTFOLIO MANAGEMENT LLC New 0 320.8K +320.8K
NORTHERN TRUST CORP Increased 75.2K 360.7K +285.5K
RENAISSANCE TECHNOLOGIES LLC Increased 473.9K 675.0K +201.1K
NOMURA HOLDINGS INC New 0 189.7K +189.7K
DIMENSIONAL FUND ADVISORS LP Increased 119.8K 291.6K +171.8K
VANGUARD CAPITAL MANAGEMENT LLC Increased 1.5M 1.7M +165.8K
MARSHALL WACE, LLP Reduced 192.9K 48.1K -144.8K
Bank of New York Mellon Corp New 0 124.4K +124.4K
CHARLES SCHWAB INVESTMENT MANAGEMENT INC New 0 115.1K +115.1K
TWO SIGMA INVESTMENTS, LP Increased 530.8K 622.9K +92.1K
VANGUARD FIDUCIARY TRUST CO Increased 199.2K 291.2K +92.0K
JANE STREET GROUP, LLC Sold Out 89.7K 0 -89.7K
ACADIAN ASSET MANAGEMENT LLC Increased 185.9K 270.3K +84.5K
Qube Research & Technologies Ltd Reduced 120.4K 38.6K -81.8K
Point72 Asset Management, L.P. Sold Out 67.4K 0 -67.4K
Nuveen, LLC New 0 63.4K +63.4K
CITADEL ADVISORS LLC New 0 51.0K +51.0K
DEUTSCHE BANK AG\ New 0 46.1K +46.1K
Catalyst Funds Management Pty Ltd Sold Out 45.6K 0 -45.6K
BANK OF AMERICA CORP /DE/ Reduced 320.2K 274.8K -45.4K
ADAR1 Capital Management, LLC Reduced 2.2M 2.1M -45.0K
WELLS FARGO & COMPANY/MN Increased 10.1K 49.7K +39.6K
PRICE T ROWE ASSOCIATES INC /MD/ New 0 39.3K +39.3K
Squarepoint Ops LLC Increased 15.0K 52.4K +37.3K
NEW YORK STATE COMMON RETIREMENT FUND New 0 36.2K +36.2K
RHUMBLINE ADVISERS New 0 35.0K +35.0K
XTX Topco Ltd New 0 32.1K +32.1K
Y-Intercept (Hong Kong) Ltd New 0 29.5K +29.5K
OMERS ADMINISTRATION Corp Sold Out 28.6K 0 -28.6K
Quantinno Capital Management LP New 0 26.8K +26.8K
Invesco Ltd. New 0 24.6K +24.6K
GOLDMAN SACHS GROUP INC Reduced 206.7K 183.9K -22.8K
MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. New 0 21.8K +21.8K
Police & Firemen's Retirement System of New Jersey New 0 19.4K +19.4K
JPMORGAN CHASE & CO Increased 1.4K 20.2K +18.7K
SIMPLEX TRADING, LLC Sold Out 17.4K 0 -17.4K
CITIGROUP INC Increased 4.5K 21.9K +17.4K
CAPTRUST FINANCIAL ADVISORS Sold Out 15.8K 0 -15.8K
Brevan Howard Capital Management LP Sold Out 15.4K 0 -15.4K
Spark Investment Management LLC New 0 14.7K +14.7K
Hudson Bay Capital Management LP Reduced 968.9K 955.0K -13.9K
PFG Investments, LLC Increased 80.9K 94.3K +13.4K
HRT FINANCIAL LP Sold Out 13.2K 0 -13.2K
JACOBS LEVY EQUITY MANAGEMENT, INC Sold Out 13.0K 0 -13.0K
STIFEL FINANCIAL CORP New 0 12.9K +12.9K
Virtu Financial LLC New 0 11.9K +11.9K
TWO SIGMA SECURITIES, LLC New 0 11.9K +11.9K
Balyasny Asset Management L.P. New 0 11.9K +11.9K
UBS Group AG Reduced 37.1K 25.8K -11.4K
Schonfeld Strategic Advisors LLC Sold Out 11.3K 0 -11.3K
Bronte Capital Management Pty Ltd. New 0 10.7K +10.7K
INTECH INVESTMENT MANAGEMENT LLC New 0 10.4K +10.4K

13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.