Who owns Annexon (ANNX)
Which tracked institutional funds hold ANNX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ANNX company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 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
47 tracked funds added or opened ANNX while 36 trimmed or exited it between 2026-Q1 and 2026-Q2 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
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
ANNX’s largest tracked holder by dollar value, FMR LLC, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in ANNX 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 2026-Q1 and 2026-Q2, across 209 tracked filers holding ANNX, 110 increased or opened the position and 113 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 ANNX between the 2026-Q1 and 2026-Q2 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 7
- MPM BIOIMPACT LLC$20M
- Logos Global Management LP$9M
- Candriam S.C.A.$7M
- PANAGORA ASSET MANAGEMENT INC$6M
- ARROWSTREET CAPITAL, LIMITED PARTNERSHIP$4M
- MOORE CAPITAL MANAGEMENT, LP$2M
Full exits 7
- ACADIAN ASSET MANAGEMENT LLC$4M
- Longaeva Partners L.P.$3M
- SILVERARC CAPITAL MANAGEMENT, LLC$3M
- Rosalind Advisors, Inc.$1M
- ALGERT GLOBAL LLC$858K
- Man Group plc$605K
Largest adds
- FMR LLC$57M
- Woodline Partners LP$27M
- GOLDMAN SACHS GROUP INC$21M
- STATE STREET CORP$18M
- BlackRock, Inc.$17M
- MAK CAPITAL ONE LLC$7M
Largest trims
- BANK OF AMERICA CORP /DE/$20M
- Redmile Group, LLC$13M
- Nuveen, LLC$8M
- BALYASNY ASSET MANAGEMENT L.P.$5M
- Bellevue Group AG$5M
- ADAGE CAPITAL PARTNERS GP, L.L.C.$4M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| FMR LLC added | 19,518,496 | $111M | 11.1% | 2026-Q2 |
| BlackRock, Inc. added | 13,539,744 | $77M | 7.7% | 2026-Q2 |
| Redmile Group, LLC trimmed | 11,869,877 | $68M | 6.8% | 2026-Q2 |
| STATE STREET CORP added | 9,824,321 | $56M | 5.6% | 2026-Q2 |
| BVF INC/IL | 8,698,173 | $50M | 5.0% | 2026-Q2 |
| Woodline Partners LP added | 6,925,067 | $40M | 4.0% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 6,871,015 | $39M | 3.9% | 2026-Q2 |
| MAK CAPITAL ONE LLC added | 5,862,180 | $33M | 3.3% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 5,825,579 | $33M | 3.3% | 2026-Q2 |
| Siren, L.L.C. added | 4,458,646 | $25M | 2.5% | 2026-Q2 |
| Bain Capital Life Sciences Investors, LLC trimmed | 4,437,731 | $25M | 2.5% | 2026-Q2 |
| Bellevue Group AG trimmed | 4,100,016 | $23M | 2.3% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 4,037,193 | $23M | 2.3% | 2026-Q2 |
| MPM BIOIMPACT LLC new | 3,544,354 | $20M | 2.0% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC added | 3,509,623 | $20M | 2.0% | 2026-Q2 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. trimmed | 3,500,000 | $20M | 2.0% | 2026-Q2 |
| GREAT POINT PARTNERS LLC added | 3,500,000 | $20M | 2.0% | 2026-Q2 |
| MORGAN STANLEY added | 3,144,453 | $18M | 1.8% | 2026-Q2 |
| Palo Alto Investors LP | 2,948,090 | $17M | 1.7% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 2,830,976 | $16M | 1.6% | 2026-Q2 |
| Nuveen, LLC trimmed | 2,765,080 | $16M | 1.6% | 2026-Q2 |
| Qube Research & Technologies Ltd trimmed | 2,749,961 | $16M | 1.6% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 2,246,800 | $13M | 1.3% | 2026-Q2 |
| Opaleye Management Inc. trimmed | 1,714,451 | $10M | 1.0% | 2026-Q2 |
| Logos Global Management LP trimmed | 1,500,000 | $9M | 0.9% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 1,497,756 | $9M | 0.9% | 2026-Q2 |
| Point72 Asset Management, L.P. trimmed | 1,382,699 | $8M | 0.8% | 2026-Q2 |
| NORTHERN TRUST CORP added | 1,352,046 | $8M | 0.8% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 1,257,799 | $7M | 0.7% | 2026-Q2 |
| Tetragon Partners GP Ltd trimmed | 1,242,455 | $7M | 0.7% | 2026-Q2 |
| Candriam S.C.A. trimmed | 1,195,142 | $7M | 0.7% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC trimmed | 1,184,931 | $7M | 0.7% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 1,105,450 | $6M | 0.6% | 2026-Q2 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ added | 1,037,366 | $6M | 0.6% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 1,004,308 | $6M | 0.6% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 978,055 | $6M | 0.6% | 2026-Q2 |
| PANAGORA ASSET MANAGEMENT INC new | 967,926 | $6M | 0.6% | 2026-Q2 |
| KENNEDY CAPITAL MANAGEMENT LLC trimmed | 898,394 | $5M | 0.5% | 2026-Q2 |
| Ishara Investments LP added | 820,000 | $5M | 0.5% | 2026-Q2 |
| Ensign Peak Advisors, Inc added | 800,516 | $5M | 0.5% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP new | 737,935 | $4M | 0.4% | 2026-Q2 |
| Y-Intercept (Hong Kong) Ltd trimmed | 734,585 | $4M | 0.4% | 2026-Q2 |
| Russell Investments Group, Ltd. trimmed | 705,291 | $4M | 0.4% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 691,812 | $4M | 0.4% | 2026-Q2 |
| Parkman Healthcare Partners LLC trimmed | 641,029 | $4M | 0.4% | 2026-Q2 |
| UBS Group AG trimmed | 623,094 | $4M | 0.4% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 616,489 | $4M | 0.4% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 614,186 | $4M | 0.4% | 2026-Q2 |
| CITADEL ADVISORS LLC trimmed | 596,582 | $3M | 0.3% | 2026-Q2 |
| DEERFIELD MANAGEMENT COMPANY, L.P. | 583,913 | $3M | 0.3% | 2026-Q2 |
| SIRIOS CAPITAL MANAGEMENT L P trimmed | 569,276 | $3M | 0.3% | 2026-Q2 |
| Schonfeld Strategic Advisors LLC added | 533,567 | $3M | 0.3% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 512,796 | $3M | 0.3% | 2026-Q2 |
| Hennion & Walsh Asset Management, Inc. trimmed | 507,050 | $3M | 0.3% | 2026-Q2 |
| Bank of New York Mellon Corp added | 501,442 | $3M | 0.3% | 2026-Q2 |
| Board of Trustees of The Leland Stanford Junior University | 482,550 | $3M | 0.3% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 459,000 | $3M | 0.3% | 2026-Q2 |
| Ikarian Capital, LLC trimmed | 430,244 | $2M | 0.2% | 2026-Q2 |
| MOORE CAPITAL MANAGEMENT, LP new | 425,332 | $2M | 0.2% | 2026-Q2 |
| Trexquant Investment LP added | 409,667 | $2M | 0.2% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP added | 406,795 | $2M | 0.2% | 2026-Q2 |
| Susquehanna Portfolio Strategies, LLC added | 395,230 | $2M | 0.2% | 2026-Q2 |
| MUTUAL OF AMERICA CAPITAL MANAGEMENT LLC trimmed | 394,600 | $2M | 0.2% | 2026-Q2 |
| Invesco Ltd. trimmed | 330,729 | $2M | 0.2% | 2026-Q2 |
| Engineers Gate Manager LP added | 319,057 | $2M | 0.2% | 2026-Q2 |
| DAFNA Capital Management LLC added | 297,812 | $2M | 0.2% | 2026-Q2 |
| Jump Financial, LLC added | 297,800 | $2M | 0.2% | 2026-Q2 |
| STATE OF WISCONSIN INVESTMENT BOARD added | 286,375 | $2M | 0.2% | 2026-Q2 |
| D. E. Shaw & Co., Inc. trimmed | 265,284 | $2M | 0.2% | 2026-Q2 |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC trimmed | 250,025 | $1M | 0.1% | 2026-Q2 |
| Swiss National Bank added | 244,600 | $1M | 0.1% | 2026-Q2 |
| CITIGROUP INC added | 235,990 | $1M | 0.1% | 2026-Q2 |
| Cinctive Capital Management LP trimmed | 215,748 | $1M | 0.1% | 2026-Q2 |
| MARSHALL WACE, LLP trimmed | 210,607 | $1M | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS added | 189,578 | $1M | 0.1% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 183,817 | $1M | 0.1% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 180,647 | $1M | 0.1% | 2026-Q2 |
| Squarepoint Ops LLC added | 173,285 | $989K | 0.1% | 2026-Q2 |
| Rafferty Asset Management, LLC trimmed | 173,279 | $989K | 0.1% | 2026-Q2 |
| OSAIC HOLDINGS, INC. added | 147,624 | $843K | 0.1% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. added | 147,240 | $816K | 0.1% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added | 134,259 | $767K | 0.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ trimmed | 129,243 | $738K | 0.1% | 2026-Q2 |
| VICTORY CAPITAL MANAGEMENT INC added | 127,338 | $727K | 0.1% | 2026-Q2 |
| BOOTHBAY FUND MANAGEMENT, LLC trimmed | 120,129 | $686K | 0.1% | 2026-Q2 |
| IEQ CAPITAL, LLC trimmed | 120,010 | $685K | 0.1% | 2026-Q2 |
| J. Goldman & Co LP trimmed | 116,046 | $663K | 0.1% | 2026-Q2 |
| XTX Topco Ltd added | 112,147 | $640K | 0.1% | 2026-Q2 |
| Vanguard Global Advisers, LLC added | 102,067 | $583K | 0.1% | 2026-Q2 |
| Quarry LP added | 100,000 | $571K | 0.1% | 2026-Q2 |
| SCS Capital Management LLC | 99,000 | $565K | 0.1% | 2026-Q2 |
| Legal & General Group Plc added | 98,118 | $560K | 0.1% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 91,661 | $521K | 0.1% | 2026-Q2 |
| MetLife Investment Management, LLC added | 91,005 | $520K | 0.1% | 2026-Q2 |
| J. Safra Sarasin Holding AG | 90,487 | $517K | 0.1% | 2026-Q2 |
| Zurcher Kantonalbank (Zurich Cantonalbank) added | 88,518 | $505K | 0.1% | 2026-Q2 |
| CAPTRUST FINANCIAL ADVISORS added | 87,909 | $502K | 0.1% | 2026-Q2 |
| PROFUND ADVISORS LLC trimmed | 87,509 | $500K | 0.0% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd | 79,486 | $454K | 0.0% | 2026-Q2 |
| DNB Asset Management AS trimmed | 73,147 | $418K | 0.0% | 2026-Q2 |
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.