Institutional HoldersBeta
Who holds a company, from every 13F filed for the quarter, one row per filer exactly as filed, against the latest share count the company reported.
Share classes (cover page of the 10-Q filed 2026-08-12, as of 2026-08-10)
| Class | Listed | Shares outstanding | Held by 13F filers | % of class | Holders | CUSIP |
|---|---|---|---|---|---|---|
| Common stock | HDRN · NASDAQ | 71,498,842 | 7,324,075 | 10.2% | — | G38648104, 40500A108 |
Each class is compared with its own share count; classes are not added together. A class that is not exchange-listed cannot be held by 13F filers.
Top holders (1 of 1 · G38648104)
change vs 2026-03-31| # | Filer | Shares | % of class | Value | Change |
|---|---|---|---|---|---|
| 1 | MIZUHO SECURITIES USA LLC | 1,453,030 | 2.03% | $15.4M | — |
Exited since 2026-03-31 (34 filers; largest 25 shown)
| TENOR CAPITAL MANAGEMENT Co., L.P. | −1,894,982 |
| BERKLEY W R CORP | −1,735,682 |
| HIGHBRIDGE CAPITAL MANAGEMENT LLC | −1,734,352 |
| TORONTO DOMINION BANK | −1,219,887 |
| AQR Arbitrage LLC | −1,105,491 |
| ARISTEIA CAPITAL, L.L.C. | −1,005,240 |
| D. E. Shaw & Co., Inc. | −990,000 |
| Yakira Capital Management, Inc. | −637,885 |
| BOOTHBAY FUND MANAGEMENT, LLC | −603,899 |
| WHITEBOX ADVISORS LLC | −550,000 |
| Westchester Capital Management, LLC | −393,423 |
| Shay Capital LLC | −344,170 |
| GOLDMAN SACHS GROUP INC | −287,598 |
| Radcliffe Capital Management, L.P. | −286,789 |
| First Trust Capital Management L.P. | −264,784 |
| Polar Asset Management Partners Inc. | −250,000 |
| Linden Advisors LP | −250,000 |
| MILLENNIUM MANAGEMENT LLC | −250,000 |
| MOORE CAPITAL MANAGEMENT, LP | −200,000 |
| Mint Tower Capital Management B.V. | −199,799 |
| RIVERNORTH CAPITAL MANAGEMENT, LLC | −185,130 |
| Clear Street Group Inc. | −122,400 |
| Ionic Capital Management LLC | −70,000 |
| CITADEL ADVISORS LLC | −56,804 |
| DLD Asset Management, LP | −50,840 |
Large holders from 13D/13G (latest per reporting person, last 2 years)
Filed when a holder crosses 5% or changes materially, so often more current than the quarter-end 13F. Percentages are the filer's own, against the share count they used.
| Reporting person | Form | Filed | Event | Shares | % of class |
|---|---|---|---|---|---|
| Highbridge Capital Management, LLC | SCHEDULE 13G/A | 2026-08-14 | 2026-06-30 | 0 | 0% |
| AQR Capital Management Holdings, LLC | SCHEDULE 13G/A | 2026-08-14 | 2026-06-30 | 1,880,054 | 2.57% |
| AQR Capital Management, LLC | SCHEDULE 13G/A | 2026-08-14 | 2026-06-30 | 1,880,054 | 2.57% |
| Aristeia Capital, L.L.C. | SCHEDULE 13G/A | 2026-08-14 | 2026-06-30 | 4,840,477 | 6.59% |
| Meteora Capital, LLC | SCHEDULE 13G/A | 2026-08-14 | 2026-06-30 | 189,000 | 0.26% |
| Robin Shah | SCHEDULE 13G/A | 2026-08-14 | 2026-06-30 | 0 | 0% |
| Tenor Capital Management Company, L.P. | SCHEDULE 13G/A | 2026-08-14 | 2026-06-30 | 0 | 0% |
| Tenor Opportunity Master Fund, Ltd. | SCHEDULE 13G/A | 2026-08-14 | 2026-06-30 | 0 | 0% |
| AQR Arbitrage, LLC | SCHEDULE 13G/A | 2026-08-14 | 2026-06-30 | 1,880,054 | 2.57% |
| Mizuho Financial Group, Inc. | SCHEDULE 13G/A | 2026-08-13 | 2026-06-30 | 0 | 0% |
| Toronto Dominion Holdings USA Inc. | SCHEDULE 13G/A | 2026-08-12 | 2026-06-30 | 0 | 0% |
| The Toronto-Dominion Bank | SCHEDULE 13G/A | 2026-08-12 | 2026-06-30 | 0 | 0% |
| TD Group US Holdings LLC | SCHEDULE 13G/A | 2026-08-12 | 2026-06-30 | 0 | 0% |
| TD SECURITIES (USA) LLC | SCHEDULE 13G/A | 2026-08-12 | 2026-06-30 | 0 | 0% |
| W. R. Berkley Corporation | SCHEDULE 13G/A | 2026-08-06 | 2026-06-30 | 0 | 0% |
| Berkley Insurance Company | SCHEDULE 13G/A | 2026-08-06 | 2026-06-30 | 0 | 0% |
| Toronto Dominion Bank | SCHEDULE 13G | 2026-05-15 | 2026-03-31 | 0 | 0% |
| Harraden Circle Special Opportunities, LP | SCHEDULE 13G/A | 2026-05-14 | 2026-03-31 | 0 | 0% |
| Harraden Circle Concentrated, LP | SCHEDULE 13G/A | 2026-05-14 | 2026-03-31 | 0 | 0% |
| Harraden Circle Investments, LLC | SCHEDULE 13G/A | 2026-05-14 | 2026-03-31 | 0 | 0% |
| Frederick V. Fortmiller, Jr. | SCHEDULE 13G/A | 2026-05-14 | 2026-03-31 | 0 | 0% |
| Harraden Circle Strategic Investments, LP | SCHEDULE 13G/A | 2026-05-14 | 2026-03-31 | 0 | 0% |
| Harraden Circle Investors GP, LLC | SCHEDULE 13G/A | 2026-05-14 | 2026-03-31 | 0 | 0% |
| Harraden Circle Investors, LP | SCHEDULE 13G/A | 2026-05-14 | 2026-03-31 | 0 | 0% |
| Harraden Circle Investors GP, LP | SCHEDULE 13G/A | 2026-05-14 | 2026-03-31 | 0 | 0% |
| THE GOLDMAN SACHS GROUP, INC. | SCHEDULE 13G/A | 2026-05-08 | 2026-03-31 | 631,845 | 3.2% |
| GOLDMAN SACHS & CO. LLC | SCHEDULE 13G/A | 2026-05-08 | 2026-03-31 | 631,845 | 3.2% |
| W.R. Berkley Corporation | SCHEDULE 13G | 2026-05-07 | 2026-03-31 | 1,735,682 | 8.7% |
| MAP 136 Segregated Portfolio, a segregated portfolio of LMA SPC | SCHEDULE 13G/A | 2026-02-17 | 2025-12-31 | 996,759 | 4.98% |
| Lighthouse Investment Partners, LLC | SCHEDULE 13G/A | 2026-02-17 | 2025-12-31 | 996,759 | 4.98% |
| Barclays PLC | SCHEDULE 13G/A | 2026-02-13 | 2025-12-31 | 0 | 0% |
| YP Management, L.L.C. | SCHEDULE 13G/A | 2026-01-14 | 2025-12-31 | 91,126 | 0.46% |
| Yakira Partners, L.P. | SCHEDULE 13G/A | 2026-01-14 | 2025-12-31 | 91,126 | 0.46% |
| MAP 136 Segregated Portfolio | SCHEDULE 13G/A | 2026-01-14 | 2025-12-31 | 546,759 | 2.73% |
| Yakira Enhanced Offshore Fund Ltd. | SCHEDULE 13G/A | 2026-01-14 | 2025-12-31 | 6,075 | 0.03% |
| Yakira Capital Management, Inc. | SCHEDULE 13G/A | 2026-01-14 | 2025-12-31 | 643,960 | 3.22% |
| Bruce M. Kallins | SCHEDULE 13G/A | 2026-01-14 | 2025-12-31 | 643,960 | 3.22% |
| Huang Rich | SCHEDULE 13G/A | 2025-11-13 | 2025-11-12 | 0 | 0% |
| Kepos Capital LP | SCHEDULE 13G/A | 2025-11-13 | 2025-09-30 | 50,000 | 0.3% |
| Mark Carhart | SCHEDULE 13G/A | 2025-11-13 | 2025-09-30 | 50,000 | 0.3% |
| RichRich Capital LLC | SCHEDULE 13G/A | 2025-11-13 | 2025-11-12 | 0 | 0% |
| KARPUS MANAGEMENT, INC. | SCHEDULE 13G/A | 2025-11-07 | 2025-10-31 | 0 | 0% |
| Westchester Capital Management, LLC | SCHEDULE 13G | 2025-05-14 | 2025-03-31 | 999,000 | 5% |
| Vik Mittal | SCHEDULE 13G/A | 2025-02-14 | 2024-12-31 | 582,610 | 2.91% |
| Ramya Rao | SCHEDULE 13G | 2025-02-14 | 2024-12-31 | 1,298,905 | 6.5% |
Source: SEC Form 13F-HR information tables for the quarter ending 2026-06-30 (filed within 45 days of quarter end; amendments applied; values normalised to dollars), the share count from the company's latest 10-K/10-Q XBRL cover page, and Schedule 13D/13G filings. Each row is a legal 13F filer as filed — related entities (e.g. Vanguard's advisers) are not merged. Retail brokerage accounts are not reported on 13F, so the remainder is mostly retail and insiders.