Quantum QMCO Institutional Ownership

NASDAQ QMCO

$16.98 -0.64 (-3.63%)

At close: Oct 22, 2026 · 4:00 PM EDT

Institutions by Trading Activity

61 Institutions

Increased 50 82.0%

Unchanged 4 6.6%

Reduced 7 11.5%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

36.71%

▲+25.70 pp QoQ

Shares Held by Institutions

14.45Mn

of 39.38Mn outstanding

▲+797.31% QoQ

Shares Outstanding

39.38Mn

24.92Mn held outside 13F filers

Institutional Investors

filed 13F for Jun 2026

▲+24 vs prior quarter

Net Shares Added (QoQ)

+12.84Mn

accumulated since last quarter

Value of Holdings

$254.67Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 10, 2026

Quantum Corp (NASDAQ:QMCO) had 61 institutional holders reporting a position on Form 13F for the quarter ended June 30, 2026.

Their combined stake equaled 36.71% of outstanding shares in Q2 2026, up from 11.00% in Q1 2026.
Total shares held in QMCO rose 797.31% from Q1 2026; the number of holders rose 84.85% from Q2 2025.
Among the 61 holders of Quantum, 50 added to their positions, 7 reduced their stakes and 4 left their positions unchanged.
The aggregate institutional position in Quantum was 14.45Mn shares at the end of Q2 2026, up 12.84Mn from the prior quarter and up 13.61Mn from a year earlier.
Alyeska Investment Group, L.P. held the largest position in QMCO at 2.65Mn shares as of June 30, 2026, or 6.74% of shares outstanding.
The largest position increases in QMCO for Q2 2026 were by Marshall Wace, LLP (+675.55K shares), Bank of America Corp (+149.65K shares), Sona Asset Management (US) LLC (+79.91K shares), Vanguard Capital Management LLC (+66.27K shares) and BlackRock, Inc. (+55.5K shares).
The largest position reductions in QMCO for Q2 2026 were by UBS Group AG (-52.96K shares), Cygnus Capital Advisors, LLC (-49.76K shares), Barclays PLC (-11.99K shares), Flagship Harbor Advisors, LLC (-6.18K shares) and Hollencrest Capital Management (-1.99K shares).
According to Business Quant data, the leading holders of QMCO for Q2 2026 were Alyeska Investment Group, L.P. (2.65Mn shares), Two Seas Capital LP (2.49Mn shares), Oaktree Capital Management LP (2.01Mn shares), Neuberger Berman Group LLC (1.16Mn shares), Ashford Capital Management Inc (1.04Mn shares), Portolan Capital Management, LLC (1.02Mn shares), Marshall Wace, LLP (713.08K shares), Vanguard Capital Management LLC (605.54K shares), Manatuck Hill Partners, LLC (350K shares) and BlackRock, Inc. (273.03K shares).

Form 13F Holdings

62 Institutional Holders

Report period 30 Jun, 2026

Total shares held 14.45Mn

Of outstanding 36.71%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	Alyeska Investment Group, L.P.	0001453072	2,653,928	6.74%	▲2,653,928	0.00%	$29.19Mn
2	Two Seas Capital LP	0001823138	2,488,535	6.32%	▲2,488,535	0.00%	$27.37Mn
3	OAKTREE CAPITAL MANAGEMENT LP	0000949509	2,011,678	5.11%	▲2,011,678	0.00%	$22.13Mn
4	Neuberger Berman Group LLC	0001465109	1,163,315	2.95%	▲1,163,315	0.00%	$12.80Mn
5	ASHFORD CAPITAL MANAGEMENT INC	0000897070	1,039,200	2.64%	▲1,039,200	0.00%	$10.55Mn
6	Portolan Capital Management, LLC	0001350290	1,020,120	2.59%	▲1,020,120	0.00%	$11.22Mn
7	MARSHALL WACE, LLP	0001318757	713,075	1.81%	▲675,547	+1,800.11%	$7.84Mn
8	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	605,541	1.54%	▲66,266	+12.29%	$6.66Mn
9	Manatuck Hill Partners, LLC	0001467902	350,000	0.89%	▲350,000	0.00%	$3.85Mn
10	BlackRock, Inc.	0002012383	273,030	0.69%	▲55,498	+25.51%	$3.00Mn
11	Cinctive Capital Management LP	0001787258	182,769	0.46%	▲182,769	0.00%	$2.01Mn
12	Bank Of America Corp /De/	0000070858	170,130	0.43%	▲149,645	+730.51%	$1.87Mn
13	GEODE CAPITAL MANAGEMENT, LLC	0001214717	164,600	0.42%	▲5,421	+3.41%	$1.81Mn
14	RENAISSANCE TECHNOLOGIES LLC	0001037389	154,516	0.39%	▲154,516	0.00%	$1.70Mn
15	SONA ASSET MANAGEMENT (US) LLC	0001856405	150,000	0.38%	▲79,908	+114.00%	$1.65Mn
16	Walleye Capital LLC	0001758720	120,044	0.30%	▲120,044	0.00%	$1.32Mn
17	Raymond James Financial Inc	0000720005	103,836	0.26%	▲103,836	0.00%	$1.14Mn
18	Centiva Capital, LP	0001692507	100,000	0.25%	▲100,000	0.00%	$1.10Mn
19	KKM Financial LLC	0002001943	90,274	0.23%	▲90,274	0.00%	$960.52K
20	VANGUARD FIDUCIARY TRUST CO	0000933478	89,125	0.23%	▲8,862	+11.04%	$980.38K

Showing 1 to 20 of 62 holders