4 institutions reported holding $1.6M of AVANTOR INC (AVTR-PA) in SEC 13F filings for 2026-03-31. Largest institutional holders: IMC-Chicago, LLC ($820,848), SIMPLEX TRADING, LLC ($438,256), GROUP ONE TRADING LLC ($346,528), SUMMIT SECURITIES GROUP LLC ($0). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | IMC-Chicago, LLC | $820,848 | 104,700 | Trimmed |
| 2 | SIMPLEX TRADING, LLC | $438,256 | 55,900 | Trimmed |
| 3 | GROUP ONE TRADING LLC | $346,528 | 44,200 | Trimmed |
| 4 | SUMMIT SECURITIES GROUP LLC | $0 | 0 | Exited |
Source: SEC Form 13F filings · as of 2026-03-31