Who owns ALXO (ALXO)
Which tracked institutional funds hold ALXO, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ALXO 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 ALXO is one-sided between 2025-Q4 and 2026-Q1: 26 added or opened and 4 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
ALXO’s largest tracked holder by dollar value, RA CAPITAL MANAGEMENT, L.P., sizes it at 0.3% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.3pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in ALXO 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 69 tracked filers holding ALXO, 43 increased or opened the position and 24 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 ALXO 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 11
- RA CAPITAL MANAGEMENT, L.P.$26M
- TCG Crossover Management, LLC$26M
- Blackstone Inc.$12M
- VANGUARD CAPITAL MANAGEMENT LLC$8M
- Vivo Capital, LLC$6M
- 5AM Venture Management, LLC$6M
Full exits 4
- VANGUARD GROUP INC$2M
- TWO SIGMA ADVISERS, LP$803K
- BANK OF MONTREAL /CAN/$537K
- DekaBank Deutsche Girozentrale$508K
Largest adds
- venBio Partners LLC$15M
- Redmile Group, LLC$12M
- Driehaus Capital Management LLC$10M
- MARSHALL WACE, LLP$7M
- Almitas Capital LLC$3M
- SUSQUEHANNA INTERNATIONAL GROUP, LLP$2M
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. new | 13,011,849 | $26M | 13.2% | 2026-Q1 |
| TCG Crossover Management, LLC new | 13,011,849 | $26M | 13.2% | 2026-Q1 |
| venBio Partners LLC added | 12,884,638 | $26M | 13.1% | 2026-Q1 |
| Redmile Group, LLC added | 7,964,188 | $16M | 8.1% | 2026-Q1 |
| Blackstone Inc. new | 5,826,544 | $12M | 5.9% | 2026-Q1 |
| Driehaus Capital Management LLC added | 5,734,620 | $11M | 5.8% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 4,179,736 | $8M | 4.2% | 2026-Q1 |
| MARSHALL WACE, LLP added | 3,757,216 | $8M | 3.8% | 2026-Q1 |
| Vivo Capital, LLC trimmed | 3,184,713 | $6M | 3.2% | 2026-Q1 |
| Almitas Capital LLC added | 3,173,834 | $6M | 3.2% | 2026-Q1 |
| 5AM Venture Management, LLC new | 3,057,325 | $6M | 3.1% | 2026-Q1 |
| ORBIMED ADVISORS LLC added | 2,866,256 | $6M | 2.9% | 2026-Q1 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. added | 2,000,000 | $4M | 2.0% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 1,988,559 | $4M | 2.0% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 1,587,833 | $3M | 1.6% | 2026-Q1 |
| Squadron Capital Management LLC new | 1,460,000 | $3M | 1.5% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 1,328,907 | $3M | 1.3% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC trimmed | 1,101,025 | $2M | 1.1% | 2026-Q1 |
| Ensign Peak Advisors, Inc added | 950,550 | $2M | 1.0% | 2026-Q1 |
| UBS Group AG added | 914,754 | $2M | 0.9% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 732,599 | $1M | 0.7% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 577,783 | $1M | 0.6% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 493,437 | $990K | 0.5% | 2026-Q1 |
| BlackRock, Inc. trimmed | 447,799 | $898K | 0.5% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 294,478 | $590K | 0.3% | 2026-Q1 |
| STATE STREET CORP added | 175,828 | $353K | 0.2% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 138,593 | $278K | 0.1% | 2026-Q1 |
| NORTHERN TRUST CORP trimmed | 136,964 | $275K | 0.1% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 107,647 | $216K | 0.1% | 2026-Q1 |
| BANK OF NOVA SCOTIA | 105,858 | $212K | 0.1% | 2026-Q1 |
| MORGAN STANLEY added | 98,835 | $198K | 0.1% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 97,881 | $196K | 0.1% | 2026-Q1 |
| JANE STREET GROUP, LLC trimmed | 95,101 | $191K | 0.1% | 2026-Q1 |
| IEQ CAPITAL, LLC | 92,233 | $185K | 0.1% | 2026-Q1 |
| Brevan Howard Capital Management LP new | 79,389 | $159K | 0.1% | 2026-Q1 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | 76,072 | $153K | 0.1% | 2026-Q1 |
| OMERS ADMINISTRATION Corp new | 75,000 | $150K | 0.1% | 2026-Q1 |
| GSA CAPITAL PARTNERS LLP trimmed | 68,987 | $138K | 0.1% | 2026-Q1 |
| XTX Topco Ltd added | 44,141 | $89K | 0.0% | 2026-Q1 |
| Point72 Asset Management, L.P. added | 41,095 | $82K | 0.0% | 2026-Q1 |
| Graham Capital Management, L.P. trimmed | 37,739 | $76K | 0.0% | 2026-Q1 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC added | 37,997 | $75K | 0.0% | 2026-Q1 |
| HC Advisors, LLC trimmed | 22,900 | $46K | 0.0% | 2026-Q1 |
| Callan Family Office, LLC trimmed | 22,419 | $45K | 0.0% | 2026-Q1 |
| CAXTON CORP new | 20,946 | $42K | 0.0% | 2026-Q1 |
| NINE MASTS CAPITAL Ltd added | 20,623 | $41K | 0.0% | 2026-Q1 |
| JSF Financial, LLC | 17,500 | $35K | 0.0% | 2026-Q1 |
| MONETA GROUP INVESTMENT ADVISORS LLC | 15,196 | $30K | 0.0% | 2026-Q1 |
| Lido Advisors, LLC | 13,220 | $27K | 0.0% | 2026-Q1 |
| FMR LLC | 12,986 | $26K | 0.0% | 2026-Q1 |
| Abel Hall, LLC | 12,598 | $25K | 0.0% | 2026-Q1 |
| Beacon Pointe Advisors, LLC new | 12,500 | $25K | 0.0% | 2026-Q1 |
| TWO SIGMA SECURITIES, LLC new | 10,993 | $22K | 0.0% | 2026-Q1 |
| Invesco Ltd. trimmed | 10,980 | $22K | 0.0% | 2026-Q1 |
| BARCLAYS PLC | 10,515 | $21K | 0.0% | 2026-Q1 |
| HSBC HOLDINGS PLC | 10,105 | $20K | 0.0% | 2026-Q1 |
| Vanguard Global Advisers, LLC new | 9,968 | $20K | 0.0% | 2026-Q1 |
| EverSource Wealth Advisors, LLC trimmed | 279 | $7K | 0.0% | 2026-Q1 |
| ROYAL BANK OF CANADA added | 1,879 | $4K | 0.0% | 2026-Q1 |
| VANGUARD GROUP INC added | 1,630,940 | $2M | 0.9% | 2025-Q4 stale |
| TANG CAPITAL MANAGEMENT LLC | 3,158,265 | $1M | 0.7% | 2025-Q2 stale |
| AMERIPRISE FINANCIAL INC added | 652,897 | $1M | 0.6% | 2025-Q3 stale |
| Privium Fund Management B.V. | 509,059 | $932K | 0.5% | 2025-Q3 stale |
| TWO SIGMA ADVISERS, LP trimmed | 710,400 | $803K | 0.4% | 2025-Q4 stale |
| BANK OF MONTREAL /CAN/ | 474,781 | $537K | 0.3% | 2025-Q4 stale |
| DekaBank Deutsche Girozentrale | 41,000 | $508K | 0.3% | 2025-Q4 stale |
| MPM BIOIMPACT LLC trimmed | 550,000 | $343K | 0.2% | 2025-Q1 stale |
| LOS ANGELES CAPITAL MANAGEMENT LLC added | 409,938 | $255K | 0.1% | 2025-Q1 stale |
| Seven Fleet Capital Management LP new | 117,817 | $133K | 0.1% | 2025-Q4 stale |
| Nuveen, LLC new | 164,790 | $103K | 0.1% | 2025-Q1 stale |
| CITADEL ADVISORS LLC added | 56,732 | $64K | 0.0% | 2025-Q4 stale |
| DEUTSCHE BANK AG\ | 101,113 | $63K | 0.0% | 2025-Q1 stale |
| Bank of New York Mellon Corp trimmed | 89,199 | $56K | 0.0% | 2025-Q1 stale |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 133,433 | $55K | 0.0% | 2025-Q2 stale |
| NAN FUNG TRINITY (HK) LTD | 41,950 | $47K | 0.0% | 2025-Q4 stale |
| D. E. Shaw & Co., Inc. trimmed | 75,900 | $47K | 0.0% | 2025-Q1 stale |
| ALLIANCEBERNSTEIN L.P. | 71,730 | $45K | 0.0% | 2025-Q1 stale |
| Aberdeen Group plc | 66,211 | $41K | 0.0% | 2025-Q1 stale |
| HRT FINANCIAL LP trimmed | 22,535 | $41K | 0.0% | 2025-Q3 stale |
| SEI INVESTMENTS CO | 60,795 | $38K | 0.0% | 2025-Q1 stale |
| RHUMBLINE ADVISERS added | 46,302 | $29K | 0.0% | 2025-Q1 stale |
| Nan Fung Group Holdings Ltd | 41,950 | $26K | 0.0% | 2025-Q1 stale |
| Point72 Asia (Singapore) Pte. Ltd. trimmed | 13,907 | $25K | 0.0% | 2025-Q3 stale |
| Squarepoint Ops LLC trimmed | 58,307 | $24K | 0.0% | 2025-Q2 stale |
| Vanguard Personalized Indexing Management, LLC trimmed | 34,577 | $22K | 0.0% | 2025-Q1 stale |
| INTECH INVESTMENT MANAGEMENT LLC added | 32,106 | $20K | 0.0% | 2025-Q1 stale |
| AQR CAPITAL MANAGEMENT LLC trimmed | 10,793 | $20K | 0.0% | 2025-Q3 stale |
| COMMONWEALTH EQUITY SERVICES, LLC trimmed | 15,102 | $17K | 0.0% | 2025-Q4 stale |
| Virtu Financial LLC new | 13,702 | $15K | 0.0% | 2025-Q4 stale |
| Cubist Systematic Strategies, LLC trimmed | 8,025 | $15K | 0.0% | 2025-Q3 stale |
| SG Americas Securities, LLC trimmed | 22,277 | $14K | 0.0% | 2025-Q1 stale |
| Forum Financial Management, LP added | 22,051 | $14K | 0.0% | 2025-Q1 stale |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 19,771 | $12K | 0.0% | 2025-Q1 stale |
| Kazazian Asset Management, LLC new | 19,000 | $12K | 0.0% | 2025-Q1 stale |
| Corebridge Financial, Inc. trimmed | 16,878 | $11K | 0.0% | 2025-Q1 stale |
| NEW YORK STATE COMMON RETIREMENT FUND | 12,522 | $8K | 0.0% | 2025-Q1 stale |
| PRICE T ROWE ASSOCIATES INC /MD/ | 10,622 | $7K | 0.0% | 2025-Q1 stale |
| MERCER GLOBAL ADVISORS INC /ADV new | 10,077 | $6K | 0.0% | 2025-Q1 stale |
| FEDERATED HERMES, INC. trimmed | 2,374 | $4K | 0.0% | 2025-Q3 stale |
| SIMPLEX TRADING, LLC added | 3,553 | $4K | 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.