9 institutions reported holding $832,588 of ROUNDHILL ETF TRUST (MSTW) in SEC 13F filings for 2026-06-30. Largest institutional holders: JANE STREET GROUP, LLC ($583,908), CITADEL ADVISORS LLC ($145,202), OLD MISSION CAPITAL LLC ($45,422), HRT FINANCIAL LP ($36,000), GROUP ONE TRADING LLC ($16,899). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | JANE STREET GROUP, LLC | $583,908 | 184,198 | New |
| 2 | CITADEL ADVISORS LLC | $145,202 | 45,805 | Added |
| 3 | OLD MISSION CAPITAL LLC | $45,422 | 14,329 | New |
| 4 | HRT FINANCIAL LP | $36,000 | 11,513 | New |
| 5 | GROUP ONE TRADING LLC | $16,899 | 5,331 | Trimmed |
| 6 | SIMPLEX TRADING, LLC | $4,168 | 1,315 | Trimmed |
| 7 | UBS Group AG | $989 | 312 | New |
| 8 | Belvedere Trading LLC | $0 | 0 | Exited |
| 9 | Root Financial Partners, LLC | $0 | 0 | Exited |
Source: SEC Form 13F filings · as of 2026-06-30