Quantum QMCO Institutional Ownership

NASDAQ QMCO

$31.89 +0.17 (+0.52%)

At close: Oct 1, 2026 · 4:00 PM EDT

Institutions by Trading Activity

62 Institutions

Increased 50 80.6%

Unchanged 5 8.1%

Reduced 7 11.3%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

65.73%

▲+53.02 pp QoQ

Shares Held by Institutions

14.45Mn

of 21.99Mn outstanding

▲+825.12% QoQ

Shares Outstanding

21.99Mn

7.53Mn held outside 13F filers

Institutional Investors

filed 13F for Jun 2026

▲+25 vs prior quarter

Net Shares Added (QoQ)

+12.89Mn

accumulated since last quarter

Value of Holdings

$458.46Mn

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

Quarter ending 30 Jun, 2026

Quantum Corp /De/ (NASDAQ:QMCO) appears in 62 institutional 13F filings for the quarter ending June 2026.

Their combined ownership stood at 65.7% of outstanding shares in June 2026, up from 12.7% in March 2026.
Their total shares held in QMCO increased 825.12% from the prior quarter, while the number of investors in Quantum increased 77.14% year over year.
Activity in QMCO broke down as 50 buyers, 7 sellers, and 5 unchanged among 62 total holders.
Combined, these investors held 14.45Mn shares in QMCO for June 2026, up by 12.89Mn shares quarter on quarter, and up 13.61Mn shares year over year.
As of June 30, 2026, the biggest holder of Quantum is Alyeska Investment Group, L.P. at 2.65Mn shares, representing 12.07% of shares outstanding.
Top purchasers of QMCO stock for the quarter ending June 2026 included Alyeska Investment Group, L.P. (2.65Mn), Two Seas Capital LP (2.49Mn), OAKTREE CAPITAL MANAGEMENT LP (2.01Mn), Neuberger Berman Group LLC (1.16Mn), ASHFORD CAPITAL MANAGEMENT INC (1.04Mn).
The largest sales of QMCO for the quarter ending June 2026 came from UBS Group AG (52.96K), Cygnus Capital Advisors, LLC (49.76K), Barclays Plc (11.99K), FLAGSHIP HARBOR ADVISORS, LLC (6.18K), HOLLENCREST CAPITAL MANAGEMENT (1.99K).
Business Quant data shows the 10 biggest positions in Quantum as of June 2026 are held by Alyeska Investment Group, L.P. (2.65Mn), Two Seas Capital LP (2.49Mn), OAKTREE CAPITAL MANAGEMENT LP (2.01Mn), Neuberger Berman Group LLC (1.16Mn), ASHFORD CAPITAL MANAGEMENT INC (1.04Mn), Portolan Capital Management, LLC (1.02Mn), MARSHALL WACE, LLP (713.08K), VANGUARD CAPITAL MANAGEMENT LLC (605.54K), Manatuck Hill Partners, LLC (350.0K), BlackRock, Inc. (273.03K).

Form 13F Holdings

62 Institutional Holders

Report period 30 Jun, 2026

Total shares held 14.45Mn

Of outstanding 65.73%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	Alyeska Investment Group, L.P.	0001453072	2,653,928	12.07%	▲2,653,928	0.00%	$29.19Mn
2	Two Seas Capital LP	0001823138	2,488,535	11.32%	▲2,488,535	0.00%	$27.37Mn
3	OAKTREE CAPITAL MANAGEMENT LP	0000949509	2,011,678	9.15%	▲2,011,678	0.00%	$22.13Mn
4	Neuberger Berman Group LLC	0001465109	1,163,315	5.29%	▲1,163,315	0.00%	$12.80Mn
5	ASHFORD CAPITAL MANAGEMENT INC	0000897070	1,039,200	4.73%	▲1,039,200	0.00%	$10.55Mn
6	Portolan Capital Management, LLC	0001350290	1,020,120	4.64%	▲1,020,120	0.00%	$11.22Mn
7	MARSHALL WACE, LLP	0001318757	713,075	3.24%	▲675,547	+1,800.11%	$7.84Mn
8	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	605,541	2.75%	▲66,266	+12.29%	$6.66Mn
9	Manatuck Hill Partners, LLC	0001467902	350,000	1.59%	▲350,000	0.00%	$3.85Mn
10	BlackRock, Inc.	0002012383	273,030	1.24%	▲55,498	+25.51%	$3.00Mn
11	Cinctive Capital Management LP	0001787258	182,769	0.83%	▲182,769	0.00%	$2.01Mn
12	Bank Of America Corp /De/	0000070858	170,130	0.77%	▲149,645	+730.51%	$1.87Mn
13	GEODE CAPITAL MANAGEMENT, LLC	0001214717	164,600	0.75%	▲5,421	+3.41%	$1.81Mn
14	RENAISSANCE TECHNOLOGIES LLC	0001037389	154,516	0.70%	▲154,516	0.00%	$1.70Mn
15	SONA ASSET MANAGEMENT (US) LLC	0001856405	150,000	0.68%	▲79,908	+114.00%	$1.65Mn
16	Walleye Capital LLC	0001758720	120,044	0.55%	▲120,044	0.00%	$1.32Mn
17	Raymond James Financial Inc	0000720005	103,836	0.47%	▲103,836	0.00%	$1.14Mn
18	Centiva Capital, LP	0001692507	100,000	0.45%	▲100,000	0.00%	$1.10Mn
19	KKM Financial LLC	0002001943	90,274	0.41%	▲90,274	0.00%	$960.52K
20	VANGUARD FIDUCIARY TRUST CO	0000933478	89,125	0.41%	▲8,862	+11.04%	$980.38K

Showing 1 to 20 of 62 holders