3 institutions reported holding $266,968 of STEM INC (STEM.WS) in SEC 13F filings for 2026-03-31. Largest institutional holders: IMC-Chicago, LLC ($132,600), SIMPLEX TRADING, LLC ($90,168), GROUP ONE TRADING LLC ($44,200). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | IMC-Chicago, LLC | $132,600 | 15,000 | Trimmed |
| 2 | SIMPLEX TRADING, LLC | $90,168 | 10,200 | Trimmed |
| 3 | GROUP ONE TRADING LLC | $44,200 | 5,000 | Trimmed |
Source: SEC Form 13F filings · as of 2026-03-31