DOUGLAS T DIETRICH
CIK 1408736 · CHAIRMAN AND CEO · last filed 2026-05-28
"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.
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Disclosed Exposure
$15.26M
Companies
2
Total Filings
90
Lifetime Open-Market Net
-$8.98M
Holdings By Company
Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Recent Filings · Page 3 of 9
90 filingsInsider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2024-05-29 | MTX | Notice (144) | −24,978 | -$2.10M | EDGAR |
| 2024-05-28 | MTX | Notice (144) | −12,010 | -$1.02M | EDGAR |
| 2024-01-29 | MTX | Mixed | +8,602 | -$705.8K | EDGAR |
| 2024-01-26 | MTX | Mixed | +4,905 | -$411.1K | EDGAR |
| 2024-01-25 | MTX | Grant (A) | — | $0 | EDGAR |
| 2023-12-08 | MTX | Mixed | +274 | -$58.4K | EDGAR |
| 2023-12-07 | MTX | Notice (144) | −13,662 | -$866.2K | EDGAR |
| 2023-01-27 | MTX | Mixed | +4,334 | -$362.3K | EDGAR |
| 2023-01-26 | MTX | Mixed | +4,268 | -$350.8K | EDGAR |
| 2023-01-25 | MTX | Mixed | +4,899 | -$410.2K | EDGAR |
Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.