QMCO Quantum Corp.

NASDAQ
$21.56

Quantum Corp. (QMCO) Institutional Ownership

What the institutions did with QMCO 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
66
filed a 13F this quarter
Managers holding
58
+22 on the quarter
Buyers
48
30 opened new
Sellers
14
8 sold out entirely
Buyer share
77.4%
of managers who traded it
Breadth
+54.8
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.

Sign in or subscribe

Largest holders

Manager Shares % of reported
Alyeska Investment Group, L.P. 2.7M 18.5%
Two Seas Capital LP 2.5M 17.3%
OAKTREE CAPITAL MANAGEMENT LP 2.0M 14.0%
NEUBERGER BERMAN GROUP LLC 1.2M 8.1%
ASHFORD CAPITAL MANAGEMENT INC 1.0M 7.2%
Portolan Capital Management, LLC 1.0M 7.1%
MARSHALL WACE, LLP 713.1K 5.0%
VANGUARD CAPITAL MANAGEMENT LLC 605.5K 4.2%
Manatuck Hill Partners, LLC 350.0K 2.4%
BlackRock, Inc. 273.0K 1.9%
Cinctive Capital Management LP 182.8K 1.3%
BANK OF AMERICA CORP /DE/ 170.1K 1.2%
GEODE CAPITAL MANAGEMENT, LLC 164.6K 1.1%
RENAISSANCE TECHNOLOGIES LLC 154.5K 1.1%
SONA ASSET MANAGEMENT (US) LLC 150.0K 1.0%
Walleye Capital LLC 120.0K 0.8%
RAYMOND JAMES FINANCIAL INC 103.8K 0.7%
Centiva Capital, LP 100.0K 0.7%
KKM Financial LLC 90.3K 0.6%
VANGUARD FIDUCIARY TRUST CO 89.1K 0.6%
Qube Research & Technologies Ltd 81.0K 0.6%
STATE STREET CORP 75.9K 0.5%
SUSQUEHANNA INTERNATIONAL GROUP, LLP 69.8K 0.5%
Man Group plc 68.6K 0.5%
Informed Momentum Co LLC 64.9K 0.5%

Largest changes

Manager Action Previous Current Change
Alyeska Investment Group, L.P. New 0 2.7M +2.7M
Two Seas Capital LP New 0 2.5M +2.5M
OAKTREE CAPITAL MANAGEMENT LP New 0 2.0M +2.0M
NEUBERGER BERMAN GROUP LLC New 0 1.2M +1.2M
ASHFORD CAPITAL MANAGEMENT INC New 0 1.0M +1.0M
Portolan Capital Management, LLC New 0 1.0M +1.0M
MARSHALL WACE, LLP Increased 37.5K 713.1K +675.5K
Manatuck Hill Partners, LLC New 0 350.0K +350.0K
Cinctive Capital Management LP New 0 182.8K +182.8K
RENAISSANCE TECHNOLOGIES LLC New 0 154.5K +154.5K
BANK OF AMERICA CORP /DE/ Increased 20.5K 170.1K +149.6K
Walleye Capital LLC New 0 120.0K +120.0K
RAYMOND JAMES FINANCIAL INC New 0 103.8K +103.8K
Centiva Capital, LP New 0 100.0K +100.0K
KKM Financial LLC New 0 90.3K +90.3K
Qube Research & Technologies Ltd New 0 81.0K +81.0K
SONA ASSET MANAGEMENT (US) LLC Increased 70.1K 150.0K +79.9K
SUSQUEHANNA INTERNATIONAL GROUP, LLP New 0 69.8K +69.8K
Man Group plc New 0 68.6K +68.6K
VANGUARD CAPITAL MANAGEMENT LLC Increased 539.3K 605.5K +66.3K
Informed Momentum Co LLC New 0 64.9K +64.9K
BlackRock, Inc. Increased 217.5K 273.0K +55.5K
UBS Group AG Reduced 99.1K 46.1K -53.0K
SEI INVESTMENTS CO New 0 38.7K +38.7K
SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC New 0 34.6K +34.6K

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.