Who owns Harvard Bioscience, Inc. (HBIO)
Which tracked institutional funds hold HBIO, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See HBIO company fundamentals →
Ownership as of the 2026-Q1 13F filings (latest filed 2026-05-15). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on HBIO is one-sided between 2025-Q4 and 2026-Q1: 1 added or opened and 4 trimmed or exited — on balance reducing.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
HBIO’s largest tracked holder by dollar value, AMH Equity Ltd, sizes it at 2.2% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 2.2pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in HBIO divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 36 tracked filers holding HBIO, 4 increased or opened the position and 63 reduced or closed it; over the same quarter, open-market insider Form 4s were net purchases.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in HBIO between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 1
- VANGUARD CAPITAL MANAGEMENT LLC$795K
Full exits 2
- VANGUARD GROUP INC$1M
- TWO SIGMA ADVISERS, LP$588K
Largest trims
- WEBER CAPITAL MANAGEMENT LLC /ADV$582K
- ACADIAN ASSET MANAGEMENT LLC$311K
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| WEBER CAPITAL MANAGEMENT LLC /ADV trimmed | 320,037 | $2M | 9.5% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC trimmed | 179,614 | $873K | 5.3% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 163,313 | $795K | 4.9% | 2026-Q1 |
| CORSAIR CAPITAL MANAGEMENT, L.P. trimmed | 124,810 | $608K | 3.7% | 2026-Q1 |
| Meros Investment Management, LP trimmed | 118,522 | $577K | 3.5% | 2026-Q1 |
| NANO CAP NEW MILLENNIUM GROWTH FUND L P trimmed | 117,500 | $572K | 3.5% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP trimmed | 114,117 | $556K | 3.4% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 101,427 | $494K | 3.0% | 2026-Q1 |
| BlackRock, Inc. trimmed | 62,226 | $303K | 1.9% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 59,511 | $290K | 1.8% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 46,332 | $226K | 1.4% | 2026-Q1 |
| Williams & Novak, LLC trimmed | 27,052 | $138K | 0.8% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 27,730 | $135K | 0.8% | 2026-Q1 |
| ESSEX INVESTMENT MANAGEMENT CO LLC trimmed | 27,021 | $132K | 0.8% | 2026-Q1 |
| JANE STREET GROUP, LLC trimmed | 23,830 | $116K | 0.7% | 2026-Q1 |
| RBF Capital, LLC trimmed | 16,000 | $78K | 0.5% | 2026-Q1 |
| STATE STREET CORP trimmed | 14,932 | $73K | 0.4% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 10,230 | $50K | 0.3% | 2026-Q1 |
| UBS Group AG trimmed | 8,405 | $41K | 0.3% | 2026-Q1 |
| CITIGROUP INC trimmed | 6,273 | $31K | 0.2% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 4,463 | $21K | 0.1% | 2026-Q1 |
| FMR LLC trimmed | 3,274 | $16K | 0.1% | 2026-Q1 |
| GROUP ONE TRADING LLC trimmed | 2,182 | $11K | 0.1% | 2026-Q1 |
| MORGAN STANLEY trimmed | 1,628 | $8K | 0.0% | 2026-Q1 |
| Vanguard Global Advisers, LLC new | 1,221 | $6K | 0.0% | 2026-Q1 |
| Tower Research Capital LLC (TRC) trimmed | 1,152 | $6K | 0.0% | 2026-Q1 |
| SBI Securities Co., Ltd. trimmed | 866 | $4K | 0.0% | 2026-Q1 |
| ROYAL BANK OF CANADA trimmed | 855 | $4K | 0.0% | 2026-Q1 |
| Brown Shipley& Co Ltd trimmed | 478 | $2K | 0.0% | 2026-Q1 |
| NISA INVESTMENT ADVISORS, LLC trimmed | 228 | $1K | 0.0% | 2026-Q1 |
| AMH Equity Ltd added | 4,047,535 | $2M | 10.9% | 2025-Q3 stale |
| VANGUARD GROUP INC added | 1,923,275 | $1M | 7.9% | 2025-Q4 stale |
| ROYCE & ASSOCIATES LP trimmed | 1,777,894 | $1M | 6.2% | 2025-Q1 stale |
| Harvey Partners, LLC trimmed | 2,050,000 | $899K | 5.5% | 2025-Q3 stale |
| HEARTLAND ADVISORS INC trimmed | 1,108,578 | $627K | 3.8% | 2025-Q1 stale |
| TWO SIGMA ADVISERS, LP added | 878,556 | $588K | 3.6% | 2025-Q4 stale |
| Portolan Capital Management, LLC added | 409,650 | $274K | 1.7% | 2025-Q4 stale |
| Granahan Investment Management, LLC trimmed | 603,519 | $265K | 1.6% | 2025-Q3 stale |
| Acuitas Investments, LLC | 491,092 | $215K | 1.3% | 2025-Q3 stale |
| BARD ASSOCIATES INC trimmed | 251,849 | $143K | 0.9% | 2025-Q1 stale |
| STRS OHIO | 206,700 | $117K | 0.7% | 2025-Q1 stale |
| Squarepoint Ops LLC added | 170,172 | $96K | 0.6% | 2025-Q1 stale |
| GSA CAPITAL PARTNERS LLP added | 168,444 | $95K | 0.6% | 2025-Q1 stale |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 139,869 | $94K | 0.6% | 2025-Q4 stale |
| Assenagon Asset Management S.A. trimmed | 139,218 | $93K | 0.6% | 2025-Q4 stale |
| Nuveen, LLC new | 139,999 | $79K | 0.5% | 2025-Q1 stale |
| PANAGORA ASSET MANAGEMENT INC trimmed | 120,381 | $68K | 0.4% | 2025-Q1 stale |
| NORTHERN TRUST CORP trimmed | 91,973 | $62K | 0.4% | 2025-Q4 stale |
| MARSHALL WACE, LLP added | 138,700 | $61K | 0.4% | 2025-Q2 stale |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 98,883 | $56K | 0.3% | 2025-Q1 stale |
| DEUTSCHE BANK AG\ added | 75,985 | $43K | 0.3% | 2025-Q1 stale |
| Virtu Financial LLC added | 59,508 | $40K | 0.2% | 2025-Q4 stale |
| GAMCO INVESTORS, INC. ET AL trimmed | 57,000 | $38K | 0.2% | 2025-Q4 stale |
| LANDSCAPE CAPITAL MANAGEMENT, L.L.C. added | 58,947 | $33K | 0.2% | 2025-Q1 stale |
| GOLDMAN SACHS GROUP INC added | 49,751 | $33K | 0.2% | 2025-Q4 stale |
| Pasadena Private Wealth, LLC trimmed | 45,000 | $30K | 0.2% | 2025-Q4 stale |
| Legato Capital Management LLC added | 43,467 | $29K | 0.2% | 2025-Q4 stale |
| CITADEL ADVISORS LLC trimmed | 42,992 | $29K | 0.2% | 2025-Q4 stale |
| XTX Topco Ltd added | 39,349 | $26K | 0.2% | 2025-Q4 stale |
| GABELLI FUNDS LLC | 39,000 | $26K | 0.2% | 2025-Q4 stale |
| RHUMBLINE ADVISERS added | 41,396 | $23K | 0.1% | 2025-Q1 stale |
| INTECH INVESTMENT MANAGEMENT LLC added | 35,911 | $20K | 0.1% | 2025-Q1 stale |
| AQR CAPITAL MANAGEMENT LLC added | 45,706 | $20K | 0.1% | 2025-Q2 stale |
| Callan Family Office, LLC trimmed | 29,791 | $20K | 0.1% | 2025-Q4 stale |
| DIMENSIONAL FUND ADVISORS LP trimmed | 27,792 | $19K | 0.1% | 2025-Q4 stale |
| GREENWOOD CAPITAL ASSOCIATES LLC | 27,754 | $19K | 0.1% | 2025-Q4 stale |
| HRT FINANCIAL LP added | 41,464 | $18K | 0.1% | 2025-Q2 stale |
| Abel Hall, LLC trimmed | 25,283 | $17K | 0.1% | 2025-Q4 stale |
| PUNCH & ASSOCIATES INVESTMENT MANAGEMENT, INC. trimmed | 25,586 | $14K | 0.1% | 2025-Q1 stale |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 25,324 | $14K | 0.1% | 2025-Q1 stale |
| SEI INVESTMENTS CO | 22,268 | $13K | 0.1% | 2025-Q1 stale |
| TWO SIGMA SECURITIES, LLC added | 17,549 | $12K | 0.1% | 2025-Q4 stale |
| Qube Research & Technologies Ltd trimmed | 17,029 | $11K | 0.1% | 2025-Q4 stale |
| Corebridge Financial, Inc. trimmed | 19,967 | $11K | 0.1% | 2025-Q1 stale |
| Vanguard Personalized Indexing Management, LLC new | 16,542 | $11K | 0.1% | 2025-Q4 stale |
| BRIGHTON JONES LLC trimmed | 25,007 | $11K | 0.1% | 2025-Q3 stale |
| SG Americas Securities, LLC added | 21,503 | $10K | 0.1% | 2025-Q2 stale |
| Point72 Asset Management, L.P. new | 14,717 | $10K | 0.1% | 2025-Q4 stale |
| BANK OF MONTREAL /CAN/ trimmed | 16,991 | $10K | 0.1% | 2025-Q1 stale |
| Invesco Ltd. trimmed | 16,899 | $10K | 0.1% | 2025-Q1 stale |
| NEW YORK STATE COMMON RETIREMENT FUND | 16,842 | $10K | 0.1% | 2025-Q1 stale |
| SIMPLEX TRADING, LLC added | 13,790 | $9K | 0.1% | 2025-Q4 stale |
| CERTUITY, LLC | 13,677 | $9K | 0.1% | 2025-Q4 stale |
| PRICE T ROWE ASSOCIATES INC /MD/ | 12,624 | $8K | 0.0% | 2025-Q1 stale |
| Y-Intercept (Hong Kong) Ltd new | 16,940 | $8K | 0.0% | 2025-Q2 stale |
| GSK plc new | 11,151 | $7K | 0.0% | 2025-Q4 stale |
| Ethic Inc. trimmed | 10,942 | $7K | 0.0% | 2025-Q4 stale |
| Verition Fund Management LLC trimmed | 12,370 | $7K | 0.0% | 2025-Q1 stale |
| Balboa Wealth Partners trimmed | 10,000 | $7K | 0.0% | 2025-Q4 stale |
| Point72 Asia (Singapore) Pte. Ltd. trimmed | 14,697 | $6K | 0.0% | 2025-Q3 stale |
| Janney Montgomery Scott LLC | 11,075 | $6K | 0.0% | 2025-Q1 stale |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | 12,500 | $5K | 0.0% | 2025-Q3 stale |
| Police & Firemen's Retirement System of New Jersey | 8,194 | $5K | 0.0% | 2025-Q1 stale |
| Legal & General Group Plc | 3,788 | $2K | 0.0% | 2025-Q1 stale |
| Ameritas Investment Partners, Inc. | 3,230 | $2K | 0.0% | 2025-Q1 stale |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM | 2,953 | $2K | 0.0% | 2025-Q1 stale |
| RAYMOND JAMES FINANCIAL INC new | 3,750 | $2K | 0.0% | 2025-Q2 stale |
| Johnson Financial Group, Inc. new | 2,000 | $1K | 0.0% | 2025-Q1 stale |
| AMALGAMATED BANK | 1,319 | $1K | 0.0% | 2025-Q1 stale |
| NORTHWESTERN MUTUAL WEALTH MANAGEMENT CO trimmed | 4 | $651 | 0.0% | 2025-Q4 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.