ANNEXON INC ANNX
COM · Common Stock · CUSIP 03589W102
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersBrisbane, CA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($391.3k this quarter). Holder counts are more reliable. Implied quarter-end price ≈ $5.54. Options: 8 managers hold calls ($6.7m notional), 4 hold puts ($875.3k).
Trends to Q1 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 73 |
| Q4 2022 | 86 |
| Q1 2023 | 102 |
| Q2 2023 | 97 |
| Q3 2023 | 95 |
| Q4 2023 | 101 |
| Q1 2024 | 129 |
| Q2 2024 | 141 |
| Q3 2024 | 143 |
| Q4 2024 | 154 |
| Q1 2025 | 149 |
| Q2 2025 | 130 |
| Q3 2025 | 144 |
| Q4 2025 | 168 |
| Q1 2026 | 217 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2024 | 90 | 61 |
| Q3 2024 | 77 | 56 |
| Q4 2024 | 84 | 56 |
| Q1 2025 | 79 | 66 |
| Q2 2025 | 68 | 72 |
| Q3 2025 | 83 | 52 |
| Q4 2025 | 111 | 44 |
| Q1 2026 | 144 | 65 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $50.4k | $153.4k | 3.05 |
| Q3 2025 | $377.2k | $405.4k | 1.07 |
| Q4 2025 | $4.3m | $2.7m | 0.63 |
| Q1 2026 | $6.7m | $875.3k | 0.13 |
Biggest buyers
| Redmile Group, LLC | Added | +4.5m |
| Siren, L.L.C. | New | +4.0m |
| BANK OF AMERICA CORP /DE/ | Added | +2.7m |
| GREAT POINT PARTNERS LLC | New | +2.5m |
| STATE STREET CORP | Added | +2.3m |
| BlackRock, Inc. | Added | +2.0m |
| MAK CAPITAL ONE LLC | Added | +1.8m |
| Point72 Asset Management, L.P. | Added | +1.5m |
| Nuveen, LLC | Added | +1.3m |
| Y-Intercept (Hong Kong) Ltd | New | +1.3m |
Biggest sellers
| Longaeva Partners L.P. | Reduced | -2.5m |
| Woodline Partners LP | Reduced | -1.7m |
| MILLENNIUM MANAGEMENT LLC | Reduced | -1.6m |
| SPHERA FUNDS MANAGEMENT LTD. | Sold out | -1.3m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -1.2m |
| AMERIPRISE FINANCIAL INC | Reduced | -899.7k |
| J. Goldman & Co LP | Reduced | -823.0k |
| Tetragon Partners GP Ltd | Reduced | -740.0k |
| Ishara Investments LP | Reduced | -575.8k |
| JACOBS LEVY EQUITY MANAGEMENT, INC | Reduced | -534.9k |
Biggest calls
| DIADEMA PARTNERS LP | Added | $2.0m353.2k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $1.4m245.5k shares |
| CITADEL ADVISORS LLC | Added | $1.3m243.6k shares |
| SIMPLEX TRADING, LLC | Added | $945.1k170.6k shares |
| GROUP ONE TRADING LLC | Added | $301.4k54.4k shares |
| UBS Group AG | New | $277.0k50.0k shares |
| JANE STREET GROUP, LLC | Reduced | $255.9k46.2k shares |
| Persistent Asset Partners Ltd | Added | $245.3k897 shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $295.8k53.4k shares |
| CITADEL ADVISORS LLC | Added | $241.5k43.6k shares |
| GROUP ONE TRADING LLC | Reduced | $194.5k35.1k shares |
| SIMPLEX TRADING, LLC | Added | $143.5k25.9k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| FMR LLC 13G · institution +4.8 pts · filed 2026-07-08 | 11.9% |
| Redmile Group, LLC 13G · passive investor no change · filed 2026-07-08 | 9.9% |
| BlackRock, Inc. 13G · institution +1.9 pts · filed 2026-07-27 | 8.0% |
| Satter Muneer A 13D · may seek influence filed 2025-11-21 | 7.2% |
| STATE STREET CORP 13G · institution new · filed 2026-08-07 | 6.0% |
| BIOTECHNOLOGY VALUE FUND L P 13G · passive investor filed 2026-05-15 | 5.4% |
Fell to 5% or below in the last year: VANGUARD GROUP INC (0.0%, 2026-03-26)
Insider purchases and sales in Q1 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q2 2024 | 1 | $49.9k | 0 | — | — |
| Q3 2024 | 1 | $53.5k | 3 | $147.6k | $129.6k |
| Q4 2024 | 1 | $36.2k | 1 | $40.1k | $40.1k |
| Q1 2025 | 0 | — | 6 | $126.4k | — |
| Q2 2025 | 1 | $10.1k | 0 | — | — |
| Q3 2025 | 1 | $31.2k | 3 | $8.0k | — |
| Q4 2025 | 3 | $8.8m | 0 | — | — |
| Q1 2026 | 1 | $45.4k | 5 | $286.4k | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-03-10 | Carson William H. Director | Bought plan | $45.4k8.0k shares |
| 2026-03-02 | ARTIS DEAN RICHARD EVP & CHIEF SCIENTIFIC OFFICER | Sold | $32.0k5.9k shares |
| 2026-03-02 | Dananberg Jamie CHIEF MEDICAL OFFICER | Sold | $31.6k5.8k shares |
| 2026-03-02 | Yednock Ted EVP & CHIEF INNOVATION OFFICER | Sold | $30.2k5.6k shares |
| 2026-03-02 | Lew Jennifer EVP & CHIEF FINANCIAL OFFICER | Sold | $30.2k5.6k shares |
| 2026-03-02 | Overdorf Michael EVP & CHIEF BUSINESS OFFICER | Sold | $23.5k4.3k shares |
| 2026-02-18 | Yednock Ted EVP & CHIEF INNOVATION OFFICER | Sold | $40.1k7.9k shares |
| 2026-02-18 | Lew Jennifer EVP & CHIEF FINANCIAL OFFICER | Sold | $40.1k7.9k shares |
| 2026-02-18 | Overdorf Michael EVP & CHIEF BUSINESS OFFICER | Sold | $31.7k6.2k shares |
| 2026-02-18 | Dananberg Jamie CHIEF MEDICAL OFFICER | Sold | $27.0k5.3k shares |
| 2026-02-18 | ARTIS DEAN RICHARD EVP & CHIEF SCIENTIFIC OFFICER | Sold | $27.0k5.3k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| Redmile Group, LLC 5.34% of their portfolio | 14.5m $80.6m | Added +4.5m |
| BlackRock, Inc. 0.00% of their portfolio | 10.9m $60.6m | Added +2.0m |
| FMR LLC 0.00% of their portfolio | 10.6m $58.9m | Added +413.2k |
| BVF INC/IL 1.54% of their portfolio | 8.7m $48.2m | Reduced -429.9k |
| STATE STREET CORP 0.00% of their portfolio | 6.9m $38.3m | Added +2.3m |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 6.0m $33.0m | First filing |
| Bain Capital Life Sciences Investors, LLC 2.60% of their portfolio | 5.2m $28.9m | Reduced -36.4k |
| Bellevue Group AG 0.68% of their portfolio | 5.2m $28.6m | Unchanged |
| MAK CAPITAL ONE LLC 4.33% of their portfolio | 4.7m $26.2m | Added +1.8m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.04% of their portfolio | 4.3m $23.8m | Reduced -1.2m |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 4.3m $23.6m | Added +2.7m |
| Nuveen, LLC 0.01% of their portfolio | 4.2m $23.5m | Added +1.3m |
| Siren, L.L.C. 0.61% of their portfolio | 4.0m $21.9m | New |
| Balyasny Asset Management L.P. 0.04% of their portfolio | 3.9m $21.5m | Added +587.7k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 3.4m $19.1m | Reduced -899.7k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 3.4m $18.7m | Added +474.9k |
| Qube Research & Technologies Ltd 0.02% of their portfolio | 3.1m $17.3m | Added +732.8k |
| Palo Alto Investors LP 2.50% of their portfolio | 2.9m $16.3m | Added +563.9k |
| MORGAN STANLEY 0.00% of their portfolio | 2.7m $15.2m | Reduced -120.2k |
| GREAT POINT PARTNERS LLC 3.39% of their portfolio | 2.5m $13.8m | New |
| Woodline Partners LP 0.05% of their portfolio | 2.3m $12.9m | Reduced -1.7m |
| Opaleye Management Inc. 1.70% of their portfolio | 2.3m $12.9m | Reduced -268.2k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 2.2m $11.9m | Added +384.1k |
| Point72 Asset Management, L.P. 0.02% of their portfolio | 1.9m $10.4m | Added +1.5m |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 1.5m $8.2m | First filing |
| Y-Intercept (Hong Kong) Ltd 0.14% of their portfolio | 1.3m $7.3m | New |
| Tetragon Partners GP Ltd 1.41% of their portfolio | 1.3m $7.2m | Reduced -740.0k |
| UBS Group AG 0.00% of their portfolio | 1.2m $6.9m | Added +868.8k |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 1.2m $6.9m | Reduced -1.6m |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 1.1m $6.1m | Added +45.4k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 1.1m $6.0m | Added +294.9k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 924.1k $5.1m | Added +205.4k |
| KENNEDY CAPITAL MANAGEMENT LLC 0.11% of their portfolio | 912.3k $5.1m | Added +272.4k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.00% of their portfolio | 903.4k $5.0m | Reduced -71 |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 888.6k $4.9m | First filing |
| MARSHALL WACE, LLP 0.01% of their portfolio | 861.5k $4.8m | Added +340.5k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 777.3k $4.3m | Added +946 |
| Invesco Ltd. 0.00% of their portfolio | 763.0k $4.2m | Reduced -209.4k |
| ACADIAN ASSET MANAGEMENT LLC 0.01% of their portfolio | 758.2k $4.2m | Reduced -103.0k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 711.4k $3.9m | Added +28.4k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 702.8k $3.9m | Reduced -343.4k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 698.7k $3.9m | Added +125.0k |
| Parkman Healthcare Partners LLC 0.39% of their portfolio | 674.0k $3.7m | Added +72.8k |
| Ensign Peak Advisors, Inc 0.01% of their portfolio | 625.1k $3.5m | New |
| Longaeva Partners L.P. 0.17% of their portfolio | 620.4k $3.4m | Reduced -2.5m |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 600.1k $3.3m | Added +324.8k |
| DEERFIELD MANAGEMENT COMPANY, L.P. 0.04% of their portfolio | 583.9k $3.2m | Unchanged |
| Ikarian Capital, LLC 0.46% of their portfolio | 580.2k $3.2m | Added +350.0k |
| SIRIOS CAPITAL MANAGEMENT L P 0.39% of their portfolio | 575.1k $3.2m | Reduced -135.2k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 562.2k $3.1m | Added +1.4k |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 544.3k $3.0m | Reduced -258.3k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 521.4k $2.9m | Added +123.3k |
| Hennion & Walsh Asset Management, Inc. 0.10% of their portfolio | 509.7k $2.8m | Reduced -25.3k |
| SILVERARC CAPITAL MANAGEMENT, LLC 0.32% of their portfolio | 496.5k $2.8m | New |
| Board of Trustees of The Leland Stanford Junior University 0.31% of their portfolio | 482.6k $2.7m | Unchanged |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 471.4k $2.6m | Added +139.4k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.01% of their portfolio | 462.1k $2.6m | New |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 428.7k $2.4m | Reduced -16.4k |
| MUTUAL OF AMERICA CAPITAL MANAGEMENT LLC 0.03% of their portfolio | 416.7k $2.3m | Reduced -225.3k |
| Trexquant Investment LP 0.02% of their portfolio | 403.7k $2.2m | New |
| Bank of New York Mellon Corp 0.00% of their portfolio | 395.0k $2.2m | Added +33.3k |
| Susquehanna Portfolio Strategies, LLC 0.03% of their portfolio | 360.3k $2.0m | Added +3.7k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 323.9k $1.6m | Added +270.2k |
| Cinctive Capital Management LP 0.10% of their portfolio | 268.6k $1.5m | Reduced -90.3k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 255.4k $1.4m | Added +193.8k |
| Swiss National Bank 0.00% of their portfolio | 236.0k $1.3m | New |
| Rafferty Asset Management, LLC 0.00% of their portfolio | 203.3k $1.1m | Added +61.6k |
| SEI INVESTMENTS CO 0.00% of their portfolio | 203.2k $1.1m | Added +145.0k |
| Rosalind Advisors, Inc. 0.45% of their portfolio | 200.0k $1.1m | New |
| IEQ CAPITAL, LLC 0.01% of their portfolio | 195.8k $1.1m | Added +12.8k |
| Ishara Investments LP 0.97% of their portfolio | 174.2k $965.3k | Reduced -575.8k |
| Engineers Gate Manager LP 0.01% of their portfolio | 174.1k $964.7k | New |
| J. Goldman & Co LP 0.04% of their portfolio | 170.8k $946.3k | Reduced -823.0k |
| BOOTHBAY FUND MANAGEMENT, LLC 0.02% of their portfolio | 166.2k $920.5k | Added +102.1k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 159.7k $884.6k | Added +33.2k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 158.6k $878.9k | Reduced -26.9k |
| ALGERT GLOBAL LLC 0.01% of their portfolio | 154.8k $857.8k | New |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.00% of their portfolio | 148.9k $825.1k | Reduced -534.9k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 134.8k $746.7k | Added +4.7k |
| DIADEMA PARTNERS LP 0.30% of their portfolio | 132.9k $736.4k | Reduced -217.1k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 130.6k $723.8k | New |
| Schonfeld Strategic Advisors LLC 0.01% of their portfolio | 123.3k $683.0k | Reduced -399.6k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 119.0k $597.6k | Reduced -21.7k |
| DAFNA Capital Management LLC 0.15% of their portfolio | 117.8k $652.7k | Reduced -155.0k |
| VICTORY CAPITAL MANAGEMENT INC 0.00% of their portfolio | 115.5k $640.0k | Added +100.8k |
| Man Group plc 0.00% of their portfolio | 109.2k $605.1k | New |
| SCS Capital Management LLC 0.01% of their portfolio | 99.0k $548.5k | New |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC 0.01% of their portfolio | 97.8k $541.8k | Reduced -40.0k |
| Connor, Clark & Lunn Investment Management Ltd. 0.00% of their portfolio | 92.7k $513.6k | New |
| PROFUND ADVISORS LLC 0.02% of their portfolio | 91.0k $503.9k | Added +38.0k |
| J. Safra Sarasin Holding AG 0.01% of their portfolio | 90.5k $501.3k | Reduced -27.3k |
| DNB Asset Management AS 0.00% of their portfolio | 88.6k $490.9k | Reduced -29.7k |
| XTX Topco Ltd 0.01% of their portfolio | 80.5k $445.9k | Reduced -162.8k |
| Legal & General Group Plc 0.00% of their portfolio | 80.0k $443.5k | Added +70.7k |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 79.5k $440.4k | First filing |
| CAPTRUST FINANCIAL ADVISORS 0.00% of their portfolio | 79.2k $438.6k | Added +47.6k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 76.3k $414.1k | Added +21.5k |
| MetLife Investment Management, LLC 0.00% of their portfolio | 72.4k $401.3k | Added +33.4k |
| POLEN CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 70.2k $388.6k | New |
| Squarepoint Ops LLC 0.00% of their portfolio | 68.0k $376.5k | New |