3 institutions reported holding $2.6M of GLADSTONE INVT CORP (GAINN1) in SEC 13F filings for 2026-06-30. Largest institutional holders: SIMPLEX TRADING, LLC ($990,986), GROUP ONE TRADING LLC ($847,208), IMC-Chicago, LLC ($734,350). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | SIMPLEX TRADING, LLC | $990,986 | 64,100 | Added |
| 2 | GROUP ONE TRADING LLC | $847,208 | 54,800 | Added |
| 3 | IMC-Chicago, LLC | $734,350 | 47,500 | Added |
Source: SEC Form 13F filings · as of 2026-06-30