4 institutions reported holding $19.2M of GARTNER INC (IT.B) in SEC 13F filings for 2026-03-31. Largest institutional holders: IMC-Chicago, LLC ($12.8M), SIMPLEX TRADING, LLC ($6.1M), GROUP ONE TRADING LLC ($332,514), HUNTINGTON NATIONAL BANK ($10). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | IMC-Chicago, LLC | $12.8M | 80,600 | Added |
| 2 | SIMPLEX TRADING, LLC | $6.1M | 38,500 | Added |
| 3 | GROUP ONE TRADING LLC | $332,514 | 2,100 | Hold |
| 4 | HUNTINGTON NATIONAL BANK | $10 | 1 | Hold |
Source: SEC Form 13F filings · as of 2026-03-31