16 insiders reported 138 Form 4 transactions for MKS INSTRUMENTS INC (MKSI) over the past 18 months (most recent 2026-08-17). Recent activity: Lee John Tseng-Chung (President & CEO) Sell 10,000 shares, Williams John Edward (EVP & GM, PSD) Sell 457 shares, Schreiner James Alan (EVP & COO) Sell 2,471 shares, Schreiner James Alan (EVP & COO) Sell 812 shares, Schreiner James Alan (EVP & COO) Sell 217 shares. Source: SEC Form 4.
| Date | Insider | Title | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-17 | Lee John Tseng-Chung | President & CEO | Sell | 10,000 | $3.0M |
| 2026-08-04 | Williams John Edward | EVP & GM, PSD | Sell | 457 | $131,758 |
| 2026-06-16 | Schreiner James Alan | EVP & COO | Sell | 2,471 | $853,790 |
| 2026-06-16 | Schreiner James Alan | EVP & COO | Sell | 812 | $281,282 |
| 2026-06-16 | Schreiner James Alan | EVP & COO | Sell | 217 | $75,299 |
| 2026-06-11 | Schreiner James Alan | EVP & COO | Sell | 781 | $247,905 |
| 2026-06-08 | McCarthy Michelle M | SVP & Chief Accounting Officer | Sell | 2,434 | $767,270 |
| 2026-06-02 | Henry David Philip | EVP, Global Str Mktg & GM, MSD | Sell | 6,000 | $1.9M |
| 2026-06-02 | Mora Elizabeth | Director | Sell | 300 | $95,406 |
| 2026-05-28 | COLELLA GERALD G | Director | Sell | 464 | $153,298 |
| 2026-05-28 | Donahue Joseph B | Director | Sell | 2,100 | $688,703 |
| 2026-05-28 | COLELLA GERALD G | Director | Sell | 8,210 | $2.7M |
| 2026-05-28 | COLELLA GERALD G | Director | Sell | 1,811 | $607,514 |
| 2026-05-28 | COLELLA GERALD G | Director | Sell | 1,626 | $547,219 |
| 2026-05-28 | COLELLA GERALD G | Director | Sell | 213 | $71,792 |
| 2026-05-28 | COLELLA GERALD G | Director | Sell | 2,800 | $948,024 |
| 2026-05-28 | COLELLA GERALD G | Director | Sell | 4,876 | $1.6M |
| 2026-05-27 | Henry David Philip | EVP, Global Str Mktg & GM, MSD | Sell | 2,500 | $826,250 |
| 2026-05-26 | Lee John Tseng-Chung | President & CEO | Sell | 10,000 | $3.2M |
| 2026-05-26 | Mayampurath Ramakumar | EVP & CFO | Sell | 8,810 | $2.8M |
| 2026-05-19 | CANNONE PETER III | Director | Sell | 1,350 | $409,590 |
| 2026-05-15 | Moloney Jacqueline F | Director | Sell | 1,000 | $312,197 |
| 2026-05-14 | Moloney Jacqueline F | Director | Sell | 1,400 | $446,586 |
| 2026-05-12 | CANNONE PETER III | Director | Buy | 782 | $0 |
| 2026-05-12 | COLELLA GERALD G | Director | Buy | 782 | $0 |
Source: SEC Form 4 filings · as of 2026-08-17