MKSI insider buying and SEC filings, explained
MKS Instruments Inc. · CIK 1049502
Tracked: Forms 3/4/5, 8-K, NT · All filings on sec.gov
Insider activity in the last 12 months
Bought
$0
Insiders who bought
0
Sold (not marked 10b5-1)
$25.5M
Planned sales (10b5-1)
$17.9M
Insider purchases and sales, last 12 months
| Traded | Type | What was filed | Source |
|---|---|---|---|
| Sep 1, 2026 | Planned (10b5-1) | Elizabeth Mora (Director) sold 300 shares at $250.96 ($75K), marked as a 10b5-1 plan trade. Holdings down 2% to 18,845 shares. | SEC filing Filed Sep 2, 2026 |
| Aug 14, 2026 | Planned (10b5-1) | John Tseng-Chung Lee (CEO and Director) sold 10,000 shares at $302.01 ($3.0M), marked as a 10b5-1 plan trade. Holdings down 7% to 134,776 shares. | SEC filing Filed Aug 17, 2026 |
| Aug 3, 2026 | Planned (10b5-1) | John Edward Williams (EVP & Gm, Psd) sold 457 shares at $288.31 ($132K), marked as a 10b5-1 plan trade. Holdings down 10% to 4,098 shares. | SEC filing Filed Aug 4, 2026 |
| Jun 12, 2026 | Sale | James Alan Schreiner (President / COO) sold 3,500 shares at about $345.82 ($1.2M). Holdings down 15% to 19,201 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Jun 16, 2026 |
| Jun 10, 2026 | Planned (10b5-1) | James Alan Schreiner (President / COO) sold 781 shares at $317.42 ($248K), marked as a 10b5-1 plan trade. Holdings down 3% to 22,701 shares. | SEC filing Filed Jun 11, 2026 |
| Jun 5, 2026 | Planned (10b5-1) | Michelle M McCarthy (SVP & Chief Accounting Officer) sold 2,434 shares at $315.23 ($767K), marked as a 10b5-1 plan trade. Holdings down 100% to 2 shares. | SEC filing Filed Jun 8, 2026 |
| Jun 1, 2026 | Sale | David Philip Henry (EVP, Global Str Mktg & GM, MSD) sold 6,000 shares at about $314.43 ($1.9M). Holdings down 37% to 10,422 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Jun 2, 2026 |
| Jun 1, 2026 | Planned (10b5-1) | Elizabeth Mora (Director) sold 300 shares at $318.02 ($95K), marked as a 10b5-1 plan trade. Holdings down 2% to 19,145 shares. | SEC filing Filed Jun 2, 2026 |
| May 27, 2026 | Sale | Joseph B Donahue (Director) sold 2,100 shares at about $327.95 ($689K). Holdings down 17% to 10,033 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed May 28, 2026 |
| May 27, 2026 | Planned (10b5-1) | Gerald G. Colella (Director) sold 20,000 shares indirectly (by trust) at about $333.40 ($6.7M), marked as a 10b5-1 plan trade. Holdings by trust down 50% to 20,017 shares. | SEC filing Filed May 28, 2026 |
| May 26, 2026 | Planned (10b5-1) | David Philip Henry (EVP, Global Str Mktg & GM, MSD) sold 2,500 shares at $330.50 ($826K), marked as a 10b5-1 plan trade. Holdings down 13% to 16,341 shares. | SEC filing Filed May 27, 2026 |
| May 22, 2026 | Planned (10b5-1) | Ramakumar Mayampurath (CFO) sold 8,810 shares at $315.48 ($2.8M), marked as a 10b5-1 plan trade. Holdings down 100% to 1 share. | SEC filing Filed May 26, 2026 |
| May 22, 2026 | Planned (10b5-1) | John Tseng-Chung Lee (CEO and Director) sold 10,000 shares at $315.48 ($3.2M), marked as a 10b5-1 plan trade. Holdings down 6% to 144,696 shares. | SEC filing Filed May 26, 2026 |
| May 18, 2026 | Sale | Peter Cannone III (Director) sold 1,350 shares at $303.40 ($410K). Holdings down 15% to 7,794 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed May 19, 2026 |
| May 14, 2026 | Sale | Jacqueline F Moloney (Director) sold 1,000 shares at $312.20 ($312K). Holdings down 10% to 8,775 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed May 15, 2026 |
| May 13, 2026 | Sale | Jacqueline F Moloney (Director) sold 1,400 shares at $318.99 ($447K). Holdings down 13% to 9,775 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed May 14, 2026 |
| May 11, 2026 | Sale | Eric Robert Taranto (EVP & Gm, Vsd) sold 2,849 shares at about $319.93 ($911K). Holdings down 18% to 12,596 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed May 12, 2026 |
| May 11, 2026 | Sale | Kathleen Flaherty Burke (EVP, GC & Secretary) sold 4,355 shares at about $319.94 ($1.4M). Holdings down 8% to 49,439 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed May 12, 2026 |
| Mar 12, 2026 | Sale | Jacqueline F Moloney (Director) sold 340 shares at about $213.77 ($73K). Holdings down 3% to 10,393 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Mar 13, 2026 |
| Mar 6, 2026 | Sale | Eric Robert Taranto (EVP & Gm, Vsd) sold 4,568 shares at about $220.52 ($1.0M). Holdings down 23% to 15,445 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Mar 9, 2026 |
| Mar 2, 2026 | Planned (10b5-1) | Elizabeth Mora (Director) sold 300 shares at $239.44 ($72K), marked as a 10b5-1 plan trade. Holdings down 2% to 18,663 shares. | SEC filing Filed Mar 3, 2026 |
| Feb 24, 2026 | Sale | James Alan Schreiner (President / COO) sold 4,100 shares at $255.00 ($1.0M). Holdings down 15% to 23,402 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 25, 2026 |
| Feb 20–24, 2026 | Sale | Gerald G. Colella (Director) sold 20,000 shares indirectly (by trust) between Feb 20 and Feb 24 at about $253.44 ($5.1M). Holdings by trust down 33% to 40,017 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 24, 2026 |
| Feb 20, 2026 | Sale | Peter Cannone III (Director) sold 1,250 shares at about $258.06 ($323K). Holdings down 13% to 8,362 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 23, 2026 |
| Feb 20, 2026 | Sale | Eric Robert Taranto (EVP & Gm, Vsd) sold 1,453 shares at $247.55 ($360K). Holdings down 7% to 20,013 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 23, 2026 |
| Feb 20, 2026 | Sale | David Philip Henry (EVP, Global Str Mktg & GM, MSD) sold 2,000 shares at $261.56 ($523K). Holdings down 10% to 18,841 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 23, 2026 |
| Feb 20, 2026 | Sale | Michelle M McCarthy (VP & Chief Accounting Officer) sold 1,466 shares at about $250.00 ($367K). Holdings down 100% to 0 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 23, 2026 |
| Feb 20, 2026 | Sale | Jacqueline F Moloney (Director) sold 829 shares at $247.55 ($205K). Holdings down 7% to 10,733 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 23, 2026 |
| Feb 20, 2026 | Sale | John Edward Williams (EVP & Gm, Psd) sold 2,043 shares at about $256.41 ($524K). Holdings down 36% to 3,640 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 23, 2026 |
| Feb 20, 2026 | Sale | Kathleen Flaherty Burke (EVP, GC & Secretary) sold 4,254 shares at $250.00 ($1.1M). Holdings down 7% to 53,794 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 23, 2026 |
| Feb 20, 2026 | Sale | John Tseng-Chung Lee (CEO and Director) sold 30,000 shares at about $256.77 ($7.7M). Holdings down 16% to 154,696 shares. Not marked as a 10b5-1 plan trade. | SEC filing Filed Feb 23, 2026 |
| Dec 2, 2025 | Planned (10b5-1) | Elizabeth Mora (Director) sold 300 shares at $158.81 ($48K), marked as a 10b5-1 plan trade. Holdings down 2% to 18,963 shares. | SEC filing Filed Dec 3, 2025 |
28 routine transactions (such as grants, option exercises or tax withholding) are not listed.
Cluster buys
No cluster buys in the last 12 months.
Red flags
No red flags in the last 12 months.
Key events
No key events in the last 12 months.
8-K filings, last 12 months
No 8-K filings in the last 12 months.
Red flags are objective triggers only: the item or form filed, never an opinion.
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