31 transactions on file (2 open-market purchases and 22 open-market sales).
22 open-market sales by MP insiders, between Mar 16, 2026 and Jun 9, 2026. A sale made under a trading plan agreed months earlier is not the same event as one decided that week, and the filing itself says which.
Discretionary. The box was on the form and was not ticked. The sale was made at the prevailing price without a pre-arranged plan behind it.
Planned (10b5-1). The filer ticked the Form 4's 10b5-1 box: the sale ran under a trading plan adopted before the trade, so it is a schedule executing rather than a view taken this week.
Not stated. The filing does not say. Either it predates the April 2023 checkbox, or nothing has re-read it since. This tab will not guess which of the two above it was.
The 2 open-market purchases on file carry no plan label. The box can be ticked on a buy, and labelling one would qualify the rarer and more informative of the two signals.
| Date | Insider | Type | Shares | Price | Value | Owned after |
|---|---|---|---|---|---|---|
| 2026-06-30 | DUCKWORTH CONNIE K Director Grant / award | Grant / award | +624 | $0.00 | +0 | 41,774 |
| 2026-06-15 | DUCKWORTH CONNIE K Director Option exercise | Option exercise | +3,998 | - | - | 41,150 |
| 2026-06-15 | Lavan Maryanne Director Option exercise | Option exercise | +3,998 | - | - | 23,753 |
| 2026-06-15 | WEISENBURGER RANDALL J Director Option exercise | Option exercise | +3,998 | - | - | 150,899 |
| 2026-06-15 | MYERS RICHARD B Director Option exercise | Option exercise | +3,998 | - | - | 7,792 |
26 more transactions are on Measure
| Insider | Role | On Sep 12, 2025 | Now | Change | Sold | Shape |
|---|---|---|---|---|---|---|
| Rosenthal Michael StuartChief Operating Officer | Chief Operating Officer | 1,316,673 | 136,622 | −89.62% | - | |
| Corbett RyanChief Financial Officer | Chief Financial Officer | 175,017 | 109,017 | −37.71% | $4.26M$4.26M on a plan | |
| Hoops Elliot DeanGeneral Counsel and Secretary | General Counsel and Secretary | 74,967 | 54,095 | −27.84% | $1.36M$1.36M on a plan |
1 more insider, included withMeasure
Each person’s holding as they reported it after each open-market trade, over the last twelve months. It counts one class of stock and excludes grants, option exercises and shares withheld for tax, so a stake can fall here while somebody’s total holding does not. Since April 2023 a Form 4 states whether a trade ran under a pre-arranged 10b5-1 plan; an older one does not, and those dollars read “not stated” rather than being counted either way.
The assistant answers from what MP has actually filed: 7 annual reports filed with the SEC, 31 Form 4 filings from the last year, 13F positions from the 2 tracked investors who hold it and 3 funds that hold it. Every figure in a reply links to the filing it came from, so an answer can be checked rather than believed.
Pressing one answers it here, from MP's filings and figures. One a day without an account; a free account has its own, and no card.
See every Form 4 MP insiders have filed, not the latest few.
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Source
From SEC Form 4 filings, filed by officers, directors and 10%-owners within two business days of a transaction. “Indirect” holdings (a trust, an LLC, a family member) are included and not distinguished from direct ones in this table.
Past transactions say nothing about future ones, and none of this is investment advice.
See who bought, not who was handed shares
Every Form 4 MP insiders file, not just the latest handful, with vesting and tax withholding struck out so what's left reads as a decision.
Every filingMeasure
Follow the investors who hold it
Each stake priced at the quarter it was filed, and diffed against the quarter before: who added, who trimmed, who left.
Every position they holdMeasure
Ask what a run of filings adds up to
Whether this is one decision or a pattern, and how it compares with MP's own history of insider activity.
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