William N. Mathis is Director at Black Stone Minerals, L.P. (BSM). They have made 4 open-market trades across 1 company since 2016, most recently 2025-10-03.
CIK 0001640004
Unrated. We grade insiders only on stock they chose to buy on the open market. Grants, option exercises and vesting say nothing about timing, so they don't count — which is why someone can file often and still have no grade. It isn't a bad sign: unrated buys beat every graded tier below A.
3 open-market purchases totalling $798K since 2016, against 1 sale. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| BSM | 246,200 | $3.7M |
Shares reported on the most recent Form 4, priced at the 2025-10-07 close.
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.