6 institutions reported holding $37.4M of WESTERN ALLIANCE BANCORP (WALPRA) in SEC 13F filings for 2026-06-30. Largest institutional holders: IMC-Chicago, LLC ($16.8M), Optiver Holding B.V. ($15.6M), SIMPLEX TRADING, LLC ($4.4M), GROUP ONE TRADING LLC ($575,400), OSAIC HOLDINGS, INC. ($0). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | IMC-Chicago, LLC | $16.8M | 204,800 | Added |
| 2 | Optiver Holding B.V. | $15.6M | 189,900 | Trimmed |
| 3 | SIMPLEX TRADING, LLC | $4.4M | 53,000 | Added |
| 4 | GROUP ONE TRADING LLC | $575,400 | 7,000 | Trimmed |
| 5 | OSAIC HOLDINGS, INC. | $0 | 0 | Exited |
| 6 | CenterStar Asset Management, LLC | $0 | 0 | Exited |
Source: SEC Form 13F filings · as of 2026-06-30