QMCO · Quantum Corp /De/ · Shareholders & Ownership
Every disclosed holder of QMCO in one list: 13F institutions, Schedule 13D and 13G filers, insiders (Forms 3, 4 and 5) and registered funds, each from its own latest filing. Holders nest by CIK and SEC reporting links, never by name, and each is summed once.
Who Owns QMCO
13F quarter Sep 30, 2026, combined view: filers that have not filed yet carry their Jun 30, 2026 positionsNo chart: the summed disclosures exceed shares outstanding, so they are not parts of one whole.
| Holder group | Shares | % Out |
|---|---|---|
| Institutional (13F) | 13,485,892 | 34.22% |
| Insiders (Forms 3, 4, 5) | 29,011,570 | 73.61% |
| 13D/G-only blocks | 135,763 | 0.34% |
| Remaining | 3,223,224 | -8.18% |
| Registered funds (N-PORT, not summed) | 901,949 | 2.29% |
Shares outstanding: 39,410,001, the issuer's latest cover-page count restated onto today's split basis.
Remaining is negative: the summed disclosures exceed shares outstanding, as when filings are dated at different times or holders that do not disclose their links count the same shares. It is flagged, not clipped.
13D/G-only counts each filer's latest 13D or 13G that no 13F report of the listing contains, that names no 13F filer and that no counted insider files. Funds are never summed: their shares sit inside their advisers' 13F reports.
Holders of QMCO
| # | Holder | Shares | As of | Notes |
|---|---|---|---|---|
| 1 |
|
16,863,839 | ||
| 1.1 |
|
14,104,620 | ||
| 2 |
|
14,145,516 | ||
| 3 |
Alyeska Investment Group, L.P.
13F
CIK 1453072 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
2,653,928 | ||
| 3.1 |
Alyeska Investment Group, L.P.
13G
CIK 1453072 · Registered investment adviser · Jun 30, 2026
Rule 13d-1(b), qualified institution, not summed
|
2,653,928 | ||
| 4 |
OAKTREE CAPITAL MANAGEMENT LP
13F
CIK 949509 · Investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
2,011,678 | ||
| 4.1 |
OAKTREE CAPITAL MANAGEMENT LP
13G
CIK 949509 · Investment adviser · Jun 30, 2026
Rule 13d-1(b), qualified institution, not summed
|
2,011,678 | ||
| 5 |
Two Seas Capital LP
13F
CIK 1823138 · Registered investment adviser · Sep 30, 2026
|
1,490,992 | ||
| 6 |
NEUBERGER BERMAN GROUP LLC
13F
CIK 1465109 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,163,315 | ||
| 7 |
ASHFORD CAPITAL MANAGEMENT INC
13F
CIK 897070 · Investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,039,200 | ||
| 8 |
Portolan Capital Management, LLC
13F
CIK 1350290 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
1,020,120 | ||
| 9 |
MARSHALL WACE, LLP
13F
CIK 1318757 · Exempt reporting adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
713,075 | ||
| 10 |
VANGUARD CAPITAL MANAGEMENT LLC
13F
CIK 2100119 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
605,541 | ||
| 11 |
VANGUARD TOTAL STOCK MARKET INDEX FUND
Fund
S000002848 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
|
420,696 | ||
| 12 |
Manatuck Hill Partners, LLC
13F
CIK 1467902 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
350,000 | ||
| 13 |
BlackRock, Inc.
13F
CIK 2012383 · Holding company · Jun 30, 2026
carried, not yet filed for the newest quarter
|
273,030 | ||
| 13.1 |
iShares Micro-Cap ETF
Fund
S000004439 · Registered fund · Jun 30, 2026
iShares Trust, not summed
|
38,870 | ||
| 14 |
Cinctive Capital Management LP
13F
CIK 1787258 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
182,769 | ||
| 15 |
VANGUARD EXTENDED MARKET INDEX FUND
Fund
S000002841 · Registered fund · Jun 30, 2026
VANGUARD INDEX FUNDS, not summed
|
170,893 | ||
| 16 |
BANK OF AMERICA CORP /DE/
13F
CIK 70858 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
|
170,130 | ||
| 17 |
GEODE CAPITAL MANAGEMENT, LLC
13F
CIK 1214717 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
164,600 | ||
| 18 |
|
163,000 | ||
| 19 |
RENAISSANCE TECHNOLOGIES LLC
13F
CIK 1037389 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
154,516 | ||
| 20 |
SONA ASSET MANAGEMENT (US) LLC
13F
CIK 1856405 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
150,000 | ||
| 21 |
Blue Torch Capital LP
13D
CIK 2050998 · Investment adviser · Feb 13, 2025
|
135,763 | ||
| 22 |
Walleye Capital LLC
13F
CIK 1758720 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
120,044 | ||
| 23 |
|
118,468 | ||
| 24 |
|
110,848 | ||
| 25 |
RAYMOND JAMES FINANCIAL INC
13F
CIK 720005 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
103,836 | ||
| 26 |
Centiva Capital, LP
13F
CIK 1692507 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
100,000 | ||
| 27 |
KKM Financial LLC
13F
CIK 2001943 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
90,274 | ||
| 28 |
Mango Growth ETF
Fund
S000098510 · Registered fund · Jul 31, 2026
ADVISORS' INNER CIRCLE FUND II, not summed
|
90,274 | ||
| 29 |
VANGUARD FIDUCIARY TRUST CO
13F
CIK 933478 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
89,125 | ||
| 30 |
Qube Research & Technologies Ltd
13F
CIK 1729829 · Exempt reporting adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
80,977 | ||
| 31 |
|
75,914 | ||
| 32 |
Cygnus Capital Advisors, LLC
13F
CIK 2114319 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
74,323 | ||
| 33 |
SUSQUEHANNA INTERNATIONAL GROUP, LLP
13F
CIK 1446194 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
69,775 | ||
| 34 |
Man Group plc
13F
CIK 1637460 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
68,593 | ||
| 35 |
Informed Momentum Co LLC
13F
CIK 1510989 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
64,857 | ||
| 36 |
|
53,139 | ||
| 37 |
|
51,675 | ||
| 38 |
|
50,000 | ||
| 39 |
|
46,106 | ||
| 40 |
|
39,000 | ||
| 41 |
SEI INVESTMENTS CO
13F
CIK 350894 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
38,739 | ||
| 42 |
SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC
13F
CIK 1446179 · Unknown · Jun 30, 2026
carried, not yet filed for the newest quarter
|
34,601 | ||
| 43 |
Squarepoint Ops LLC
13F
CIK 1642575 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
33,817 | ||
| 44 |
NORTHERN TRUST CORP
13F
CIK 73124 · Bank · Jun 30, 2026
carried, not yet filed for the newest quarter
|
33,220 | ||
| 45 |
|
32,402 | ||
| 46 |
|
28,736 | ||
| 47 |
PRICE T ROWE ASSOCIATES INC /MD/
13F
CIK 80255 · Registered investment adviser · Jun 30, 2026
carried, not yet filed for the newest quarter
|
25,069 | ||
| 47.1 |
T. Rowe Price Extended Equity Market Index Fund
Fund
S000002090 · Registered fund · Jun 30, 2026
T. ROWE PRICE INDEX TRUST, INC., not summed
|
11,000 | ||
| 48 |
|
25,000 | ||
| 49 |
|
25,000 | ||
| 50 |
|
24,971 |
Shares are restated onto today's split basis. Change compares each row with the same holder's previous filing in the same source; a dash means there is none to compare. Nested 13D/G, insider and fund rows are not summed, since a 13F report already holds them.
Showing 1–50 of 93 holders
Create a free account to page through every holder, filter by source and group by ultimate parent.