ABOS Acumen Pharmaceuticals, Inc.

NASDAQ
$3.03

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 reporting
113
filed a 13F this quarter
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

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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

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.