3 institutions reported holding $340,516 of STEM INC (STEM.WS) in SEC 13F filings for 2026-06-30. Largest institutional holders: IMC-Chicago, LLC ($282,722), SIMPLEX TRADING, LLC ($33,583), GROUP ONE TRADING LLC ($24,211). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | IMC-Chicago, LLC | $282,722 | 36,200 | Added |
| 2 | SIMPLEX TRADING, LLC | $33,583 | 4,300 | Trimmed |
| 3 | GROUP ONE TRADING LLC | $24,211 | 3,100 | Trimmed |
Source: SEC Form 13F filings · as of 2026-06-30