QUANTUM CORP (QMCO)
Institutional ownership reported to the SEC as of Q2 2026, across 31 quarters.
63
Reporting holders
$163.4M
Reported value
36.5%
Of shares outstanding
3.9%
Held as options
+28
Holder change
Institutions report 14,353,813 shares against 39,374,500 outstanding. Shares only - option lines are excluded, which is why this can be compared with the company at all. The count comes from the cover page of the company's own most recent report, so it is dated when that was filed rather than at quarter end.
Options share is the part of reported value carried in derivative lines rather than shares. A high figure means institutions are expressing a view on this security without owning much of it.
Holders
| Filer | Value | Shares | Their book | Held | Change |
|---|---|---|---|---|---|
| Alyeska Investment Group, L.P. | $29.2M | 2,653,928 | 0.08% | new | NEW |
| Two Seas Capital LP | $27.4M | 2,488,535 | 0.54% | new | NEW |
| OAKTREE CAPITAL MANAGEMENT LP | $22.1M | 2,011,678 | 0.31% | new | NEW |
| NEUBERGER BERMAN GROUP LLC | $12.8M | 1,163,315 | 0.01% | new | NEW |
| Portolan Capital Management, LLC | $11.2M | 1,020,120 | 0.42% | new | NEW |
| ASHFORD CAPITAL MANAGEMENT INC | $10.6M | 1,039,200 | 1.13% | new | NEW |
| MARSHALL WACE, LLP | $7.8M | 713,075 | 0.01% | 3q | +1800.1%+$7.4M |
| VANGUARD CAPITAL MANAGEMENT LLC | $6.7M | 605,541 | 0.00% | 2q | +12.3%+$728.9K |
| Manatuck Hill Partners, LLC | $3.9M | 350,000 | 1.28% | new | NEW |
| BlackRock, Inc. | $3.0M | 273,030 | 0.00% | 8q | +25.5%+$610.5K |
| SONA ASSET MANAGEMENT (US) LLC | $2.8M | 150,000 | 0.06% | 2q | +114.0%+$1.5M |
| JANE STREET GROUP, LLC | $2.3M | options only | 0.00% | new | OPTIONS |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | $2.2M | 69,775 | 0.00% | new | NEW |
| Cinctive Capital Management LP | $2.0M | 182,769 | 0.07% | new | NEW |
| BANK OF AMERICA CORP /DE/ | $1.9M | 170,130 | 0.00% | 8q | +730.5%+$1.6M |
| GEODE CAPITAL MANAGEMENT, LLC | $1.8M | 164,600 | 0.00% | 8q | +3.4%+$59.7K |
| RENAISSANCE TECHNOLOGIES LLC | $1.7M | 154,516 | 0.00% | new | NEW |
| CITADEL ADVISORS LLC | $1.5M | options only | 0.00% | new | OPTIONS |
| Walleye Capital LLC | $1.3M | 120,044 | 0.00% | new | NEW |
| RAYMOND JAMES FINANCIAL INC | $1.1M | 103,836 | 0.00% | new | NEW |
| Centiva Capital, LP | $1.1M | 100,000 | 0.01% | new | NEW |
| VANGUARD FIDUCIARY TRUST CO | $980.4K | 89,125 | 0.00% | 2q | +11.0%+$97.5K |
| KKM Financial LLC | $960.5K | 90,274 | 0.13% | new | NEW |
| Qube Research & Technologies Ltd | $890.7K | 80,977 | 0.00% | new | NEW |
| STATE STREET CORP | $835.1K | 75,914 | 0.00% | 8q | +4.3%+$34.1K |
| Man Group plc | $754.5K | 68,593 | 0.00% | new | NEW |
| Informed Momentum Co LLC | $713.4K | 64,857 | 0.06% | new | NEW |
| UBS Group AG | $507.2K | 46,106 | 0.00% | 8q | -53.5%-$582.6K |
| SEI INVESTMENTS CO | $426.1K | 38,739 | 0.00% | new | NEW |
| SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC | $380.6K | 34,601 | 0.01% | new | NEW |
| Squarepoint Ops LLC | $372.0K | 33,817 | 0.00% | new | NEW |
| NORTHERN TRUST CORP | $365.4K | 33,220 | 0.00% | 8q | +15.5%+$49.0K |
| MILLENNIUM MANAGEMENT LLC | $239.3K | 21,755 | 0.00% | new | NEW |
| GOLDMAN SACHS GROUP INC | $210.7K | 19,153 | 0.00% | new | NEW |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | $178.6K | 16,240 | 0.00% | 2q | HELD |
| MORGAN STANLEY | $170.4K | 15,492 | 0.00% | 8q | +2.1%+$3.4K |
| CITIGROUP INC | $158.7K | 14,426 | 0.00% | new | NEW |
| Kovack Advisors, Inc. | $146.8K | 13,430 | 0.01% | 2q | +7.6%+$10.4K |
| Schonfeld Strategic Advisors LLC | $132.6K | 12,055 | 0.00% | new | NEW |
| WELLS FARGO & COMPANY/MN | $124.3K | 11,300 | 0.00% | 7q | +37.0%+$33.5K |
| FLAGSHIP HARBOR ADVISORS, LLC | $121.0K | 11,004 | 0.00% | 4q | -36.0%-$68.0K |
| Invesco Ltd. | $119.2K | 10,839 | 0.00% | new | NEW |
| TUDOR INVESTMENT CORP ET AL | $114.4K | options only | 0.00% | new | OPTIONS |
| Vanguard Global Advisers, LLC | $66.0K | 6,000 | 0.00% | 2q | HELD |
| JPMORGAN CHASE & CO | $43.6K | 3,680 | 0.00% | 8q | +45900.0%+$43.5K |
| JONES FINANCIAL COMPANIES LLLP | $18.4K | 1,580 | 0.00% | 6q | +7.7%+$1.3K |
| BNP PARIBAS FINANCIAL MARKETS | $13.1K | 1,187 | 0.00% | 8q | +354.8%+$10.2K |
| FEDERATED HERMES, INC. | $12.7K | 1,158 | 0.00% | 3q | +38.7%+$3.6K |
| SBI Securities Co., Ltd. | $11.8K | 1,070 | 0.00% | 7q | -46.6%-$10.3K |
| ROYAL BANK OF CANADA | $8.0K | 765 | 0.00% | 5q | +497.7%+$6.7K |
| Tower Research Capital LLC (TRC) | $7.2K | 655 | 0.00% | new | NEW |
| OSAIC HOLDINGS, INC. | $5.3K | 485 | 0.00% | 8q | -49.7%-$5.3K |
| BARCLAYS PLC | $5.0K | 455 | 0.00% | 8q | -96.3%-$131.9K |
| MERCER GLOBAL ADVISORS INC /ADV | $2.8K | 250 | 0.00% | new | NEW |
| HARBOUR INVESTMENTS, INC. | $2.0K | 183 | 0.00% | new | NEW |
| FMR LLC | $1.2K | 106 | 0.00% | new | NEW |
| EFG International AG | $1.1K | 100 | 0.00% | 3q | HELD |
| Global Retirement Partners, LLC | $715 | 65 | 0.00% | 2q | HELD |
| Continuum Advisory, LLC | $374 | 34 | 0.00% | new | NEW |
| PRICE T ROWE ASSOCIATES INC /MD/ | $276 | 25,069 | 0.00% | 3q | +15.0% |
| Quarry LP | $187 | 17 | 0.00% | new | NEW |
| HOLLENCREST CAPITAL MANAGEMENT | $110 | 10 | 0.00% | 2q | -99.5%-$21.9K |
| Farther Finance Advisors, LLC | $44 | 4 | 0.00% | 8q | HELD |
| NewEdge Advisors, LLC | $0 | 0 | 0.00% | new | NEW |
Five percent filings
Anyone crossing 5% of a company must say so within days - far sooner than the next quarterly holdings report. A 13D declares an intent to influence the company; a 13G is the passive version. See all activist filings →
| Filed | Form | Filer | % of class |
|---|---|---|---|
| 2026-08-14 | 13G | Two Seas Capital LPwith 2 co-filers | 6.3% |
| 2026-08-14 | 13G | Alyeska Investment Group, L.P.with 2 co-filers | 6.7% |
| 2026-08-10 | 13G | Oaktree Capital Management LP | 5.1% |
Quarter by quarter
Coverage begins with the quarter ending 2018-12-31. Earlier filings exist only as occasional late amendments, too sparse to describe a market, so they are not shown.
| Quarter | Holders | Value | Shares | New | Added | Trimmed | Options |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 63 | $163.4M | 14,353,813 | 35 | 17 | 6 | 3.9% |
| Q1 2026 | 35 | $7.0M | 1,468,963 | 7 | 7 | 10 | 0.0% |
| Q4 2025 | 37 | $12.7M | 1,969,717 | 13 | 13 | 7 | 0.0% |
| Q3 2025 | 28 | $8.6M | 864,858 | 3 | 13 | 4 | 0.0% |
| Q2 2025 | 33 | $9.0M | 902,084 | 11 | 9 | 8 | 0.0% |
| Q1 2025 | 27 | $24.0M | 1,669,647 | 6 | 13 | 3 | 0.0% |
| Q4 2024 | 43 | $96.6M | 1,797,761 | 21 | 5 | 5 | 2.0% |
| Q3 2024 | 26 | $8.0M | 2,274,509 | 25 | 0 | 0 | 0.0% |
| Q2 2024 | 46 | $19.4M | 47,693,882 | 4 | 12 | 10 | 0.0% |
| Q1 2024 | 56 | $28.6M | 48,844,299 | 8 | 12 | 11 | 0.1% |
| Q4 2023 | 56 | $17.7M | 50,660,794 | 8 | 8 | 16 | 0.0% |
| Q3 2023 | 57 | $34.4M | 56,345,139 | 8 | 8 | 17 | 0.0% |
| Q2 2023 | 60 | $62.5M | 57,699,063 | 5 | 15 | 14 | 0.0% |
| Q1 2023 | 64 | $67.6M | 58,880,242 | 9 | 16 | 18 | 0.0% |
| Q4 2022 | 60 | $67.8M | 62,168,120 | 7 | 10 | 26 | 0.0% |
| Q3 2022 | 76 | $69.0M | 63,190,681 | 10 | 19 | 24 | 0.0% |
| Q2 2022 | 87 | $93.6M | 64,630,062 | 21 | 28 | 25 | 0.0% |
| Q1 2022 | 89 | $99.0M | 40,565,186 | 17 | 19 | 34 | 0.1% |
| Q4 2021 | 103 | $232.0M | 41,965,231 | 15 | 32 | 35 | 0.6% |
| Q3 2021 | 95 | $227.9M | 43,083,672 | 7 | 42 | 22 | 0.5% |
| Q2 2021 | 108 | $297.0M | 42,091,437 | 21 | 46 | 29 | 1.4% |
| Q1 2021 | 102 | $334.4M | 40,671,542 | 26 | 41 | 20 | 0.3% |
| Q4 2020 | 85 | $181.9M | 31,623,061 | 12 | 27 | 27 | 0.8% |
| Q3 2020 | 79 | $133.0M | 30,487,453 | 13 | 22 | 24 | 0.4% |
| Q2 2020 | 74 | $99.4M | 27,940,359 | 34 | 18 | 9 | 0.0% |
| Q1 2020 | 50 | $51.3M | 17,397,896 | 48 | 0 | 1 | 0.0% |
| Q4 2019 | 3 | $962.0K | 220,406 | 0 | 0 | 0 | 0.0% |
| Q3 2019 | 3 | $742.0K | 220,406 | 0 | 0 | 1 | 0.0% |
| Q2 2019 | 3 | $425.0K | 250,406 | 0 | 1 | 0 | 0.0% |
| Q1 2019 | 7 | $1.0M | 421,863 | 2 | 1 | 2 | 0.7% |
| Q4 2018 | 58 | $35.6M | 17,727,457 | 2 | 1 | 1 | 0.5% |