ANNEXON INC (ANNX) Institutional Buying Activity
Institutional investors tracked by InsiderSet increased exposure to ANNEXON INC (ANNX) during the quarter ended March 31, 2026 through a combination of new purchases and expanded existing positions disclosed in SEC Form 13F filings.
The largest institutional buyer of ANNX during the latest reporting period was Renaissance Technologies LLC, which increased its reported ANNX position by approximately $1.29M based on quarter-end filing values. Several additional hedge funds and long-term asset managers also reported meaningful increases in ANNX exposure during the quarter.
Institutional buying activity can provide insight into investor conviction, sector allocation trends, and smart money positioning toward ANNEXON INC (ANNX). InsiderSet tracks quarterly accumulation trends, new institutional positions, ownership increases, and estimated performance of newly disclosed holdings using SEC filing data and recent market prices.
The investors highlighted on this page collectively added approximately $2.40M in reported ANNX exposure during the latest filing period, reflecting continued institutional interest in ANNEXON INC's growth initiatives and strategic positioning.
| Portfolio quarter | Name | Type | Quantity | Remaining | Reported stock balance |
|---|---|---|---|---|---|
| Q1 2026 | Polen Capital Management | Buy | 70,152 | 70,152 | $388,642 |
| Q4 2025 | Renaissance Technologies LLC | Buy | 49,021 | 802,600 | $4,029,052 |
| Q1 2025 | Renaissance Technologies LLC | Buy | 668,737 | 1,162,437 | $2,243,503 |
| Q4 2024 | Renaissance Technologies LLC | Buy | 92,300 | 493,700 | $2,532,681 |
| Q1 2024 | Renaissance Technologies LLC | Buy | 187,000 | 671,200 | $4,813 |
| Q3 2023 | Renaissance Technologies LLC | Buy | 139,110 | 561,310 | $1,325 |
| Q2 2023 | Renaissance Technologies LLC | Buy | 65,100 | 422,200 | $1,486 |
| Q1 2023 | Renaissance Technologies LLC | Buy | 47,000 | 357,100 | $1,375 |
| Q1 2022 | Renaissance Technologies LLC | Buy | 495,629 | 596,529 | $1,629 |
| Q4 2021 | Renaissance Technologies LLC | Buy | 100,900 | 100,900 | $1,159 |
Frequently asked questions about ANNX activity
Which institutional owners are buying ANNX?
Institutional owners buying ANNX include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.
What does "buy" mean in ANNX activity?
"Buy" means an investor increased their reported position in ANNX compared to the prior reporting period. This reflects growing exposure to ANNEXON INC (ANNX) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).
Is institutional interest in ANNX increasing?
Institutional interest in ANNX can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.