Who owns ABOS (ABOS)
Which tracked institutional funds hold ABOS, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ABOS company fundamentals →
Ownership as of the 2026-Q1 13F filings. 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 ABOS is one-sided between 2025-Q4 and 2026-Q1: 15 added or opened and 5 trimmed or exited — on balance accumulating.
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
ABOS’s largest tracked holder by dollar value, RA CAPITAL MANAGEMENT, L.P., sizes it at 0.5% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.5pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in ABOS 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 84 tracked filers holding ABOS, 52 increased or opened the position and 21 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
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 ABOS 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$4M
Full exits 3
- VANGUARD GROUP INC$3M
- TWO SIGMA ADVISERS, LP$890K
- CITADEL ADVISORS LLC$729K
Largest adds
- RA CAPITAL MANAGEMENT, L.P.$18M
- Alyeska Investment Group, L.P.$4M
- ADAR1 Capital Management, LLC$3M
- Ikarian Capital, LLC$2M
- Sands Capital Alternatives, LLC$2M
- TWO SIGMA INVESTMENTS, LP$951K
Largest trims
- FMR LLC$2M
- Laurion Capital Management LP$589K
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 |
|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. added | 20,992,669 | $50M | 43.0% | 2026-Q1 |
| Sands Capital Alternatives, LLC added | 3,720,105 | $9M | 7.6% | 2026-Q1 |
| Alyeska Investment Group, L.P. added | 2,454,754 | $6M | 5.0% | 2026-Q1 |
| FRANKLIN RESOURCES INC | 2,305,096 | $5M | 4.7% | 2026-Q1 |
| ADAR1 Capital Management, LLC added | 2,156,334 | $5M | 4.4% | 2026-Q1 |
| Knollwood Investment Advisory, LLC | 1,628,510 | $4M | 3.3% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 1,506,277 | $4M | 3.1% | 2026-Q1 |
| FMR LLC trimmed | 1,157,346 | $3M | 2.4% | 2026-Q1 |
| Ikarian Capital, LLC added | 1,053,797 | $2M | 2.2% | 2026-Q1 |
| Hudson Bay Capital Management LP added | 968,940 | $2M | 2.0% | 2026-Q1 |
| Pathstone Holdings, LLC | 859,110 | $2M | 1.8% | 2026-Q1 |
| SG Americas Securities, LLC added | 719,257 | $2M | 1.5% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 659,675 | $2M | 1.4% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 601,476 | $1M | 1.2% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 530,812 | $1M | 1.1% | 2026-Q1 |
| Laurion Capital Management LP trimmed | 525,444 | $1M | 1.1% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 473,946 | $1M | 1.0% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 416,238 | $983K | 0.9% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 320,216 | $756K | 0.7% | 2026-Q1 |
| BOOTHBAY FUND MANAGEMENT, LLC added | 273,012 | $644K | 0.6% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 206,683 | $488K | 0.4% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 199,226 | $470K | 0.4% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC added | 185,850 | $435K | 0.4% | 2026-Q1 |
| MARSHALL WACE, LLP added | 178,929 | $422K | 0.4% | 2026-Q1 |
| BlackRock, Inc. added | 178,326 | $421K | 0.4% | 2026-Q1 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC added | 176,171 | $416K | 0.4% | 2026-Q1 |
| STATE STREET CORP added | 151,728 | $358K | 0.3% | 2026-Q1 |
| MORGAN STANLEY trimmed | 144,584 | $341K | 0.3% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 120,388 | $284K | 0.2% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 119,756 | $282K | 0.2% | 2026-Q1 |
| CATALYST FINANCIAL PARTNERS LLC | 89,699 | $212K | 0.2% | 2026-Q1 |
| JANE STREET GROUP, LLC trimmed | 89,661 | $212K | 0.2% | 2026-Q1 |
| PFG Investments, LLC added | 80,850 | $191K | 0.2% | 2026-Q1 |
| NORTHERN TRUST CORP | 75,212 | $178K | 0.2% | 2026-Q1 |
| Point72 Asset Management, L.P. added | 67,375 | $159K | 0.1% | 2026-Q1 |
| Prospera Financial Services Inc | 50,000 | $118K | 0.1% | 2026-Q1 |
| Catalyst Funds Management Pty Ltd added | 45,600 | $108K | 0.1% | 2026-Q1 |
| Verdad Advisers, LP new | 37,278 | $88K | 0.1% | 2026-Q1 |
| UBS Group AG added | 37,146 | $88K | 0.1% | 2026-Q1 |
| Rangeley Capital, LLC new | 35,000 | $83K | 0.1% | 2026-Q1 |
| BARCLAYS PLC added | 30,679 | $72K | 0.1% | 2026-Q1 |
| Intrepid Financial Planning Group LLC | 30,150 | $71K | 0.1% | 2026-Q1 |
| OMERS ADMINISTRATION Corp added | 28,600 | $67K | 0.1% | 2026-Q1 |
| AXQ CAPITAL, LP new | 28,487 | $67K | 0.1% | 2026-Q1 |
| Independent Advisor Alliance | 19,000 | $45K | 0.0% | 2026-Q1 |
| PINNACLE ASSOCIATES LTD | 18,020 | $43K | 0.0% | 2026-Q1 |
| Pinnacle Wealth Management Advisory Group, LLC | 18,020 | $43K | 0.0% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC trimmed | 17,929 | $42K | 0.0% | 2026-Q1 |
| SIMPLEX TRADING, LLC added | 17,414 | $41K | 0.0% | 2026-Q1 |
| Factor Wealth Management LTD | 16,500 | $39K | 0.0% | 2026-Q1 |
| CAPTRUST FINANCIAL ADVISORS added | 15,757 | $37K | 0.0% | 2026-Q1 |
| Brevan Howard Capital Management LP trimmed | 15,385 | $36K | 0.0% | 2026-Q1 |
| Squarepoint Ops LLC added | 15,015 | $35K | 0.0% | 2026-Q1 |
| HRT FINANCIAL LP trimmed | 13,162 | $31K | 0.0% | 2026-Q1 |
| JACOBS LEVY EQUITY MANAGEMENT, INC trimmed | 13,011 | $31K | 0.0% | 2026-Q1 |
| SEI INVESTMENTS CO trimmed | 11,564 | $27K | 0.0% | 2026-Q1 |
| Mesirow Financial Investment Management, Inc. new | 11,305 | $27K | 0.0% | 2026-Q1 |
| Schonfeld Strategic Advisors LLC trimmed | 11,300 | $27K | 0.0% | 2026-Q1 |
| Integrated Wealth Concepts LLC | 10,179 | $24K | 0.0% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN added | 10,108 | $24K | 0.0% | 2026-Q1 |
| ROYAL BANK OF CANADA added | 7,090 | $17K | 0.0% | 2026-Q1 |
| Vanguard Global Advisers, LLC new | 6,684 | $16K | 0.0% | 2026-Q1 |
| OSAIC HOLDINGS, INC. trimmed | 5,351 | $13K | 0.0% | 2026-Q1 |
| CITIGROUP INC added | 4,486 | $11K | 0.0% | 2026-Q1 |
| PNC FINANCIAL SERVICES GROUP, INC. | 3,080 | $7K | 0.0% | 2026-Q1 |
| Rockefeller Capital Management L.P. | 3,000 | $7K | 0.0% | 2026-Q1 |
| TFC Financial Management, Inc. | 2,500 | $6K | 0.0% | 2026-Q1 |
| EverSource Wealth Advisors, LLC trimmed | 22 | $5K | 0.0% | 2026-Q1 |
| VANGUARD GROUP INC added | 1,653,772 | $3M | 3.0% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP trimmed | 421,800 | $890K | 0.8% | 2025-Q4 stale |
| CITADEL ADVISORS LLC trimmed | 345,283 | $729K | 0.6% | 2025-Q4 stale |
| Y-Intercept (Hong Kong) Ltd added | 250,848 | $291K | 0.3% | 2025-Q2 stale |
| Invesco Ltd. added | 127,798 | $141K | 0.1% | 2025-Q1 stale |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 116,902 | $129K | 0.1% | 2025-Q1 stale |
| DEUTSCHE BANK AG\ | 96,995 | $107K | 0.1% | 2025-Q1 stale |
| XTX Topco Ltd added | 49,563 | $105K | 0.1% | 2025-Q4 stale |
| Quadrature Capital Ltd new | 49,046 | $103K | 0.1% | 2025-Q4 stale |
| Bank of New York Mellon Corp trimmed | 90,258 | $99K | 0.1% | 2025-Q1 stale |
| Nuveen, LLC new | 78,446 | $86K | 0.1% | 2025-Q1 stale |
| GSA CAPITAL PARTNERS LLP | 32,103 | $55K | 0.0% | 2025-Q3 stale |
| AQR CAPITAL MANAGEMENT LLC added | 46,292 | $54K | 0.0% | 2025-Q2 stale |
| RHUMBLINE ADVISERS trimmed | 45,516 | $50K | 0.0% | 2025-Q1 stale |
| Jain Global LLC new | 39,990 | $46K | 0.0% | 2025-Q2 stale |
| Cubist Systematic Strategies, LLC added | 23,904 | $41K | 0.0% | 2025-Q3 stale |
| Marex Group plc | 33,300 | $39K | 0.0% | 2025-Q2 stale |
| INTECH INVESTMENT MANAGEMENT LLC added | 28,540 | $31K | 0.0% | 2025-Q1 stale |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 25,171 | $28K | 0.0% | 2025-Q1 stale |
| Point72 Asia (Singapore) Pte. Ltd. trimmed | 16,044 | $27K | 0.0% | 2025-Q3 stale |
| Vanguard Personalized Indexing Management, LLC added | 22,006 | $24K | 0.0% | 2025-Q1 stale |
| TWO SIGMA SECURITIES, LLC added | 20,066 | $23K | 0.0% | 2025-Q2 stale |
| Virtu Financial LLC trimmed | 10,922 | $23K | 0.0% | 2025-Q4 stale |
| Corebridge Financial, Inc. trimmed | 20,550 | $23K | 0.0% | 2025-Q1 stale |
| NINE MASTS CAPITAL Ltd new | 10,637 | $22K | 0.0% | 2025-Q4 stale |
| Savant Capital, LLC | 11,045 | $19K | 0.0% | 2025-Q3 stale |
| THOROUGHBRED FINANCIAL SERVICES, LLC new | 15,500 | $17K | 0.0% | 2025-Q1 stale |
| PRICE T ROWE ASSOCIATES INC /MD/ | 13,616 | $15K | 0.0% | 2025-Q1 stale |
| DRW Securities, LLC new | 11,018 | $13K | 0.0% | 2025-Q2 stale |
| Ethic Inc. new | 11,377 | $13K | 0.0% | 2025-Q2 stale |
| NEW YORK STATE COMMON RETIREMENT FUND | 9,800 | $11K | 0.0% | 2025-Q1 stale |
| Ameritas Investment Partners, Inc. | 4,110 | $5K | 0.0% | 2025-Q1 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.