2 institutions reported holding $33,696 of MIDDLESEX WTR CO (MSEXP) in SEC 13F filings for 2026-06-30. Largest institutional holders: SIMPLEX TRADING, LLC ($28,080), GROUP ONE TRADING LLC ($5,616). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | SIMPLEX TRADING, LLC | $28,080 | 500 | Trimmed |
| 2 | GROUP ONE TRADING LLC | $5,616 | 100 | New |
Source: SEC Form 13F filings · as of 2026-06-30