Quantum Corp. 13F holders
61 funds reported a position in Quantum Corp. in their 13F for the quarter ended 30 June 2026, together 14.5 million shares worth $158.1 million. Against the quarter before, 31 opened a position, 18 added, 7 trimmed and 8 sold out; together they bought a net 12.8 million shares. The largest holders: Alyeska Investment Group, L.P., Two Seas Capital LP and Oaktree Capital Management LP.
Funds holding61+24 on Q1 2026
Shares they held14.5Mworth $158.1 million
Net bought on the quarter12.8M sharesabout $140.5 million at the funds' values
Funds buying to selling49 to 15opened or added, to cut or sold
Opened 31Added 18Held 5Trimmed 7Sold out 8
What each fund did in QMCO against its 13F for the quarter before; a change under 0.1% of a holding counts as held
Funds reporting a position in QMCO in their 13F, each quarter; hover a bar for the shares they held
Filed so far for the quarter to 30 September 2026
3,241 funds have filed their 13F for the quarter so far; the rest are due by 16 November 2026. Of those, 13 reported a position in Quantum Corp.: 8 opened one, 1 added, 1 trimmed and 0 sold out, a net 965,548 shares sold.
| Fund | Change in shares | Shares now | Status | Filing |
|---|---|---|---|---|
| Two Seas Capital LP | -997,543 | 1,490,992 | trimmed | 13F |
| Y-Intercept (Hong Kong) Ltd | +21,886 | 21,886 | new | 13F |
| TRUE Private Wealth Advisors | +6,645 | 6,645 | new | 13F |
| State of Alaska, Department of Revenue | +1,936 | 1,936 | new | 13F |
| Signaturefd, LLC | +696 | 696 | new | 13F |
| Carolina Wealth Advisors, LLC | +416 | 416 | new | 13F |
| SBI Securities Co., Ltd. | +254 | 1,324 | added | 13F |
| Caitong International Asset Management Co., Ltd | +121 | 121 | new | 13F |
| Blue Bell Private Wealth Management, LLC | +34 | 34 | new | 13F |
| Cassaday & Co Wealth Management LLC | +7 | 7 | new | 13F |
The largest moves in the name among the funds that have filed, against each fund's previous 13F.
The well-known funds
Of the 44 funds followed here, 5 reported a position in Quantum Corp. in a 13F for the quarter ended 30 June 2026. The largest: Alyeska, 2.7 million shares worth $29.2 million, 0.1% of its reported book. New this quarter: Alyeska, Renaissance Technologies, Millennium Management, FMR LLC. In the quarter, 5 funds added or opened a position and 0 trimmed or sold out; together they bought a net 2.8 million shares, about $31.2 million at the funds' own value per share on 30 June 2026. A change under 0.1% of a holding counts as held.
| Fund | Shares | Value | Of its book | Change on the quarter | Status | Quarter ended | Filing |
|---|---|---|---|---|---|---|---|
| Alyeska | 2,653,928 | $29.2 million | 0.1% | +2,653,928 | new | 30 June 2026 | 13F |
| Geode Capital Management | 164,600 | $1.8 million | 0.0% | +5,421 | added | 30 June 2026 | 13F |
| Renaissance Technologies | 154,516 | $1.7 million | 0.0% | +154,516 | new | 30 June 2026 | 13F |
| Millennium Management | 21,755 | $239,305 | 0.0% | +21,755 | new | 30 June 2026 | 13F |
| FMR LLC | 106 | $1,166 | 0.0% | +106 | new | 30 June 2026 | 13F |
Value is what the fund reported.
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Change is shares against the fund's previous 13F; a fund with one filing read shows no change. 13Fs cover long US positions of managers above $100 million and are filed up to 45 days after the quarter.The largest holders
| Fund | Shares | Share of all | Value | Of its book | Change in shares | Filing |
|---|---|---|---|---|---|---|
| Alyeska Investment Group, L.P. | 2,653,928 | 18.36% | $29.2 million | 0.07% | new | 13F |
| Two Seas Capital LP | 2,488,535 | 17.22% | $27.4 million | 1.04% | new | 13F |
| Oaktree Capital Management LP | 2,011,678 | 13.92% | $22.1 million | 0.59% | new | 13F |
| Neuberger Berman Group LLC | 1,163,315 | 8.05% | $12.8 million | 0.01% | new | 13F |
| Portolan Capital Management, LLC | 1,020,120 | 7.06% | $11.2 million | 0.42% | new | 13F |
| Ashford Capital Management Inc. | 1,039,200 | 7.19% | $10.6 million | 1.13% | new | 13F |
| Marshall Wace, LLP | 713,075 | 4.93% | $7.8 million | 0.01% | +675,547 | 13F |
| Vanguard Capital Management LLC | 605,541 | 4.19% | $6.7 million | 0.00% | +66,266 | 13F |
| Manatuck Hill Partners, LLC | 350,000 | 2.42% | $3.9 million | 1.28% | new | 13F |
| BlackRock, Inc. | 273,030 | 1.89% | $3.0 million | 0.00% | +55,498 | 13F |
| Cinctive Capital Management LP | 182,769 | 1.26% | $2.0 million | 0.08% | new | 13F |
| Bank of America Corp. | 170,130 | 1.18% | $1.9 million | 0.00% | +149,645 | 13F |
| Geode Capital Management, LLC | 164,600 | 1.14% | $1.8 million | 0.00% | +5,421 | 13F |
| Renaissance Technologies LLC | 154,516 | 1.07% | $1.7 million | 0.00% | new | 13F |
| Sona Asset Management (us) LLC | 150,000 | 1.04% | $1.6 million | 0.07% | +79,908 | 13F |
| Walleye Capital LLC | 120,044 | 0.83% | $1.3 million | 0.01% | new | 13F |
| Raymond James Financial Inc. | 103,836 | 0.72% | $1.1 million | 0.00% | new | 13F |
| Centiva Capital, LP | 100,000 | 0.69% | $1.1 million | 0.04% | new | 13F |
| Vanguard Fiduciary Trust Co. | 89,125 | 0.62% | $980,375 | 0.00% | +8,862 | 13F |
| KKM Financial LLC | 90,274 | 0.62% | $960,515 | 0.13% | new | 13F |
| Qube Research & Technologies Ltd | 80,977 | 0.56% | $890,747 | 0.00% | new | 13F |
| State Street Corp. | 75,914 | 0.53% | $835,054 | 0.00% | +3,100 | 13F |
| Cygnus Capital Advisors, LLC | 74,323 | 0.51% | $818,000 | 0.56% | -49,763 | 13F |
| Susquehanna International Group, LLP | 69,775 | 0.48% | $767,525 | 0.00% | new | 13F |
| Man Group plc | 68,593 | 0.47% | $754,523 | 0.00% | new | 13F |
| Informed Momentum Co LLC | 64,857 | 0.45% | $713,427 | 0.06% | new | 13F |
| UBS Group AG | 46,106 | 0.32% | $507,166 | 0.00% | -52,962 | 13F |
| Sei Investments Co. | 38,739 | 0.27% | $426,150 | 0.00% | new | 13F |
| Susquehanna Fundamental Investments, LLC | 34,601 | 0.24% | $380,611 | 0.01% | new | 13F |
| Squarepoint Ops LLC | 33,817 | 0.23% | $371,987 | 0.00% | new | 13F |
| Northern Trust Corp. | 33,220 | 0.23% | $365,420 | 0.00% | +4,458 | 13F |
| Price T Rowe Associates Inc. | 25,069 | 0.17% | $276,000 | 0.00% | +3,268 | 13F |
| Millennium Management LLC | 21,755 | 0.15% | $239,305 | 0.00% | new | 13F |
| Goldman Sachs Group Inc. | 19,153 | 0.13% | $210,683 | 0.00% | new | 13F |
| Bridgeway Capital Management, LLC | 16,240 | 0.11% | $178,640 | 0.00% | no change | 13F |
| Morgan Stanley | 15,492 | 0.11% | $170,412 | 0.00% | +313 | 13F |
| Citigroup Inc. | 14,426 | 0.10% | $158,686 | 0.00% | new | 13F |
| Kovack Advisors, Inc. | 13,430 | 0.09% | $146,790 | 0.01% | +950 | 13F |
| Schonfeld Strategic Advisors LLC | 12,055 | 0.08% | $132,605 | 0.00% | new | 13F |
| Wells Fargo & Company | 11,300 | 0.08% | $124,300 | 0.00% | +7,175 | 13F |
| Flagship Harbor Advisors, LLC | 11,004 | 0.08% | $121,044 | 0.01% | -6,181 | 13F |
| Invesco Ltd. | 10,839 | 0.07% | $119,229 | 0.00% | new | 13F |
| Vanguard Global Advisers, LLC | 6,000 | 0.04% | $66,000 | 0.00% | no change | 13F |
| JPMorgan Chase & Co. | 3,680 | 0.03% | $43,608 | 0.00% | +3,672 | 13F |
| Jones Financial Companies Lllp | 1,580 | 0.01% | $18,407 | 0.00% | +113 | 13F |
| BNP Paribas Financial Markets | 1,187 | 0.01% | $13,057 | 0.00% | +926 | 13F |
| Federated Hermes, Inc. | 1,158 | 0.01% | $12,738 | 0.00% | +323 | 13F |
| SBI Securities Co., Ltd. | 1,070 | 0.01% | $11,770 | 0.00% | -934 | 13F |
| Royal Bank of Canada | 765 | 0.01% | $8,000 | 0.00% | +637 | 13F |
| Tower Research Capital LLC (TRC) | 655 | 0.00% | $7,205 | 0.00% | new | 13F |
The 50 largest of the 61 funds that reported a position in QMCO in their 13F for the quarter ended 30 June 2026, by the value each reported.
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Share of all is the fund's part of all the shares the funds reported. Change is shares against the fund's 13F for the quarter before. A 13F lists a manager's long positions in US-listed shares at the quarter's end. What is a 13F?Options the funds reported on QMCO
| Fund | Option | Shares under the options | Value of those shares | Quarter ended | Filing |
|---|---|---|---|---|---|
| Citadel Advisors | Calls | 116,200 | $1.3 million | 30 June 2026 | 13F |
| Citadel Advisors | Puts | 20,600 | $226,600 | 30 June 2026 | 13F |
A 13F lists calls and puts by the shares they cover and what those shares were worth at the quarter's end, not what the options cost.
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They are not counted in the holdings above. A put gains when the stock falls, a call when it rises, and a fund may hold either to hedge.Schedule 13D and 13G filed on the name, last twelve months
| Filed | Schedule | Who | Holding | Of the class | Event date | Rule or purpose | Filing |
|---|---|---|---|---|---|---|---|
| 14 August 2026 | 13G | Alyeska Investment Group, L.P. and 5 others | 2.7 million | 6.7% | 30 June 2026 | passive, institutional (13d-1(b)) | EDGAR |
| 14 August 2026 | 13G | Two Seas Capital LP and 5 others | 2.5 million | 6.3% | 30 June 2026 | passive, institutional (13d-1(b)) | EDGAR |
| 10 August 2026 | 13G | Oaktree Capital Management LP and 1 other | 2.0 million | 5.1% | 30 June 2026 | passive, institutional (13d-1(b)) | EDGAR |
| 8 June 2026 | 13D/A | Dialectic Technology SPV LLC and 2 others | 16.9 million | 40.0% | 4 June 2026 | Item 4 of the Amended Statement is hereby amended by adding the following paragraphs to the end of Item 4: Entry into Conversion Agreement On June 4, 2026 (the "Closing"), the Company issued and sold to certain accredited investors in a pri | EDGAR |
| 12 January 2026 | 13D/A | Dialectic Technology SPV LLC and 2 others | 9.7 million | 41.4% | 8 January 2026 | Item 4 of the Amended Statement is hereby amended by adding the following paragraphs to the end of Item 4: January 8, 2026 Conversion Price Adjustment Notice On January 8, 2026, the Issuer notified Dialectic that, effective after the close | EDGAR |
| 22 December 2025 | 13D/A | Dialectic Technology SPV LLC and 2 others | 8.1 million | 37.3% | 18 December 2025 | Item 4 of the Original Statement is hereby amended by deleting the heading "Convertible Notes" and the two paragraphs thereunder and replacing them with the following: Consummation of Debt Exchange, Convertible Notes, Indenture and Note Reg | EDGAR |
A Schedule 13D is filed by anyone who crosses 5% of a class with intent to influence; a 13G by a passive holder.
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Amendments (/A) report a change, including an exit to zero. Holding and percentage are as the filer stated them on the cover page; the purpose is the filer's own words, cut short. 13D and 13GFails to deliver
| Settlement date | Shares failed | Price | File |
|---|---|---|---|
| 28 September 2026 | 42 | $31.68 | SEC |
| 22 September 2026 | 4,367 | $26.10 | SEC |
| 21 September 2026 | 930 | $25.09 | SEC |
| 15 September 2026 | 200 | $22.83 | SEC |
| 11 September 2026 | 200 | $23.03 | SEC |
| 8 September 2026 | 7 | $24.73 | SEC |
| 20 August 2026 | 352 | $21.79 | SEC |
Shares that failed to deliver at settlement, per day, from the SEC's half-month files, which arrive about two weeks after the period.