20 institutions reported holding $18.5M of ROUNDHILL ETF TRUST (MARS) in SEC 13F filings for 2026-06-30. Largest institutional holders: SUSQUEHANNA INTERNATIONAL GROUP, LLP ($7.9M), OLD MISSION CAPITAL LLC ($3.7M), JANE STREET GROUP, LLC ($3.1M), CITADEL ADVISORS LLC ($1.7M), MGO ONE SEVEN LLC ($740,287). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | $7.9M | 245,624 | New |
| 2 | OLD MISSION CAPITAL LLC | $3.7M | 113,376 | New |
| 3 | JANE STREET GROUP, LLC | $3.1M | 96,422 | Added |
| 4 | CITADEL ADVISORS LLC | $1.7M | 51,549 | New |
| 5 | MGO ONE SEVEN LLC | $740,287 | 22,912 | New |
| 6 | Cambridge Investment Research Advisors, Inc. | $397,000 | 12,280 | New |
| 7 | PRELUDE CAPITAL MANAGEMENT, LLC | $323,100 | 10,000 | New |
| 8 | SIMPLEX TRADING, LLC | $275,862 | 8,538 | New |
| 9 | UBS Group AG | $274,183 | 8,486 | Added |
| 10 | GROUP ONE TRADING LLC | $97,253 | 3,010 | New |
| 11 | OSAIC HOLDINGS, INC. | $18,028 | 558 | New |
| 12 | Steward Partners Investment Advisory, LLC | $6,947 | 215 | New |
| 13 | AE Wealth Management LLC | $4,200 | 130 | New |
| 14 | CNB Bank | $3,231 | 100 | New |
| 15 | Newbridge Financial Services Group, Inc. | $969 | 30 | New |
| 16 | Ameritas Advisory Services, LLC | $969 | 30 | New |
| 17 | Farther Finance Advisors, LLC | $246 | 8 | New |
| 18 | Main Street Group, LTD | $65 | 2 | New |
| 19 | GTS SECURITIES LLC | $0 | 0 | Exited |
| 20 | Bogart Wealth, LLC | $0 | 0 | Exited |
Source: SEC Form 13F filings · as of 2026-06-30