Insider txns (12m)
177
Stock / equity
MKSI MKS INC
- Company
- MKS INC
- Security
- Equity
- Size, estimated from filings
- Large cap ($10B – $200B)
- Insiders on record
- 16
- Members of Congress
- 1
- Latest trade on record
- September 1, 2026
MKSI (MKS INC) has 177 disclosed insider transactions from 16 insiders in the last 12 months (0 open-market buys, 58 sales, about $58.6M at reported prices) and 3 congressional trades from 1 member of Congress. The most recent disclosure was filed September 2, 2026.
Open-market buys / sales
0 / 58
Congress trades (12m)
3
Distinct filers (12m)
17
Share price
Price and chart by TradingView for MKS INC. US share prices here are delayed, not real-time. The trade records on this page come from government filings, not from this chart.
MKSI in charts
Who is trading this stock
Which people account for the buying and selling over the last 12 months?
BoughtSold
8 people account for the disclosed buying and selling in MKSI over the last 12 months; the most active is Lee John Tseng-Chung with $23M.
Prices insiders traded at
What price did insiders buy and sell at? Each marker is one open-market trade at the share price reported on its Form 4.
▲ Bought▼ SoldAverage reported price that day
Insiders reported 47 open-market trades in MKSI since Oct 1, 2025, at prices from $122 to $347; the most recent was a sale at $251 on Sep 1, 2026. These are the prices on the filings, not adjusted for stock splits, and not a market price series.
Insider holdings over time
Is an insider building or unwinding a position? Shares held directly after each filing.
Moloney Jacqueline FMora Elizabeth
Moloney Jacqueline F reported 8,775 shares held after the latest filing, against 11,562 at the first on record.
Federal contracts by agency
Which agencies awarded MKS INC contracts that started in the last 180 days?
Federal contract awards to MKS INC that started in the last 180 days have a combined award value of $100K, most from Department of Commerce.
Insiders trading MKSI
Everyone who filed a Form 4 for this ticker, by number of rows on record. "Bought" and "sold" count open-market purchases (code P) and sales only; awards, option exercises and shares withheld for tax are in the row count but not in those two columns. Showing 15 of 16.
| Insider | Role | Rows | Bought | Sold | Value bought | Value sold | Latest |
|---|---|---|---|---|---|---|---|
| Burke Kathleen Flaherty | EVP, GC & Secretary | 28 | 0 | 4 | — | $4.0M | May 11, 2026 |
| Lee John Tseng-Chung | President & CEO | 26 | 0 | 8 | — | $22.7M | August 14, 2026 |
| Schreiner James Alan | EVP & COO | 21 | 0 | 7 | — | $3.7M | June 12, 2026 |
| Henry David Philip | EVP, Global Str Mktg & GM, MSD | 18 | 0 | 4 | — | $4.3M | June 1, 2026 |
| Taranto Eric Robert | EVP & GM, VSD | 18 | 0 | 4 | — | $3.0M | May 11, 2026 |
| Williams John Edward | EVP & GM, PSD | 16 | 0 | 4 | — | $1.2M | August 3, 2026 |
| McCarthy Michelle M | SVP & Chief Accounting Officer | 11 | 0 | 4 | — | $1.5M | June 5, 2026 |
| Mayampurath Ramakumar | EVP & CFO | 11 | 0 | 3 | — | $3.8M | May 22, 2026 |
| COLELLA GERALD G | Director | 10 | 0 | 9 | — | $11.7M | May 27, 2026 |
| Moloney Jacqueline F | Director | 6 | 0 | 5 | — | $1.1M | May 14, 2026 |
| Mora Elizabeth | Director | 5 | 0 | 4 | — | $290K | September 1, 2026 |
| CANNONE PETER III | Director | 3 | 0 | 2 | — | $732K | May 18, 2026 |
| Donahue Joseph B | Director | 2 | 0 | 1 | — | $689K | May 27, 2026 |
| Donlan Renee Martel | EVP, GC & CCO | 1 | 0 | 0 | — | — | August 17, 2026 |
| Batra Raj | Director | 1 | 0 | 0 | — | — | May 11, 2026 |
What kind of transactions these are 4 Form 4 codes
| Code | Meaning | Rows | Shares | Value at reported prices |
|---|---|---|---|---|
| M | Option exercise or conversion | 96 | 265,201 | — |
| S | Open-market sale | 47 | 152,049 | $43.5M |
| A | Grant or award | 23 | 123,561 | — |
| F | Shares withheld for tax | 12 | 60,340 | $15.1M |
What each code means: Form 4 transaction codes.
Members of Congress trading MKSI
Members whose periodic transaction reports name this ticker. Amounts are the sums of the ranges as filed.
| Member | Seat | Trades | Bought | Sold | Range as filed | Latest |
|---|---|---|---|---|---|---|
| Lisa C. McClain | Representative (MI, District 9), Republican | 3 | 1 | 2 | $3,003–$45K | October 31, 2025 |
Insider transactions
| Filer | Side | Trade date | Disclosed | Lag | Shares | Price | Value | Flags | Source | Share |
|---|---|---|---|---|---|---|---|---|---|---|
| Mora Elizabeth | Sell S | September 1, 2026 | September 2, 2026 | 1d | 300 | $251 | $75K | 10b5-1 plan | Form 4 ↗ | |
| Donlan Renee Martel | Other A | August 17, 2026 | August 18, 2026 | 1d | 954 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Sell S | August 14, 2026 | August 17, 2026 | 3d | 10,000 | $302 | $3.0M | 10b5-1 plan | Form 4 ↗ | |
| Williams John Edward | Sell S | August 3, 2026 | August 4, 2026 | 1d | 457 | $288 | $132K | 10b5-1 plan | Form 4 ↗ | |
| Schreiner James Alan | Sell S | June 12, 2026 | June 16, 2026 | 4d | 217 | $347 | $75K | Form 4 ↗ | ||
| Schreiner James Alan | Sell S | June 12, 2026 | June 16, 2026 | 4d | 812 | $346 | $281K | Form 4 ↗ | ||
| Schreiner James Alan | Sell S | June 12, 2026 | June 16, 2026 | 4d | 2,471 | $346 | $854K | Form 4 ↗ | ||
| Schreiner James Alan | Sell S | June 10, 2026 | June 11, 2026 | 1d | 781 | $317 | $248K | 10b5-1 plan | Form 4 ↗ | |
| McCarthy Michelle M | Sell S | June 5, 2026 | June 8, 2026 | 3d | 2,434 | $315 | $767K | 10b5-1 plan | Form 4 ↗ | |
| Mora Elizabeth | Sell S | June 1, 2026 | June 2, 2026 | 1d | 300 | $318 | $95K | 10b5-1 plan | Form 4 ↗ | |
| Henry David Philip | Sell S | June 1, 2026 | June 2, 2026 | 1d | 6,000 | $314 | $1.9M | Form 4 ↗ | ||
| COLELLA GERALD G | Sell S | May 27, 2026 | May 28, 2026 | 1d | 2,800 | $339 | $948K | 10b5-1 planindirect | Form 4 ↗ | |
| COLELLA GERALD G | Sell S | May 27, 2026 | May 28, 2026 | 1d | 213 | $337 | $72K | 10b5-1 planindirect | Form 4 ↗ | |
| COLELLA GERALD G | Sell S | May 27, 2026 | May 28, 2026 | 1d | 1,626 | $337 | $547K | 10b5-1 planindirect | Form 4 ↗ | |
| COLELLA GERALD G | Sell S | May 27, 2026 | May 28, 2026 | 1d | 1,811 | $335 | $608K | 10b5-1 planindirect | Form 4 ↗ | |
| COLELLA GERALD G | Sell S | May 27, 2026 | May 28, 2026 | 1d | 4,876 | $332 | $1.6M | 10b5-1 planindirect | Form 4 ↗ | |
| COLELLA GERALD G | Sell S | May 27, 2026 | May 28, 2026 | 1d | 8,210 | $331 | $2.7M | 10b5-1 planindirect | Form 4 ↗ | |
| COLELLA GERALD G | Sell S | May 27, 2026 | May 28, 2026 | 1d | 464 | $330 | $153K | 10b5-1 planindirect | Form 4 ↗ | |
| Donahue Joseph B | Sell S | May 27, 2026 | May 28, 2026 | 1d | 2,100 | $328 | $689K | Form 4 ↗ | ||
| Henry David Philip | Sell S | May 26, 2026 | May 27, 2026 | 1d | 2,500 | $331 | $826K | 10b5-1 plan | Form 4 ↗ | |
| Mayampurath Ramakumar | Sell S | May 22, 2026 | May 26, 2026 | 4d | 8,810 | $315 | $2.8M | 10b5-1 plan | Form 4 ↗ | |
| Lee John Tseng-Chung | Sell S | May 22, 2026 | May 26, 2026 | 4d | 10,000 | $315 | $3.2M | 10b5-1 plan | Form 4 ↗ | |
| CANNONE PETER III | Sell S | May 18, 2026 | May 19, 2026 | 1d | 1,350 | $303 | $410K | Form 4 ↗ | ||
| Moloney Jacqueline F | Sell S | May 14, 2026 | May 15, 2026 | 1d | 1,000 | $312 | $312K | Form 4 ↗ | ||
| Moloney Jacqueline F | Sell S | May 13, 2026 | May 14, 2026 | 1d | 1,400 | $319 | $447K | Form 4 ↗ | ||
| Taranto Eric Robert | Sell S | May 11, 2026 | May 12, 2026 | 1d | 2,849 | $320 | $911K | Form 4 ↗ | ||
| Moloney Jacqueline F | Other A | May 11, 2026 | May 12, 2026 | 1d | 782 | — | — | Form 4 ↗ | ||
| JABRE WISSAM G | Other A | May 11, 2026 | May 12, 2026 | 1d | 782 | — | — | Form 4 ↗ | ||
| Mora Elizabeth | Other A | May 11, 2026 | May 12, 2026 | 1d | 782 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Sell S | May 11, 2026 | May 12, 2026 | 1d | 4,355 | $320 | $1.4M | Form 4 ↗ | ||
| Donahue Joseph B | Other A | May 11, 2026 | May 12, 2026 | 1d | 782 | — | — | Form 4 ↗ | ||
| CANNONE PETER III | Other A | May 11, 2026 | May 12, 2026 | 1d | 782 | — | — | Form 4 ↗ | ||
| Batra Raj | Other A | May 11, 2026 | May 12, 2026 | 1d | 782 | — | — | Form 4 ↗ | ||
| COLELLA GERALD G | Other A | May 11, 2026 | May 12, 2026 | 1d | 782 | — | — | Form 4 ↗ | ||
| Williams John Edward | Option / conversion M | April 17, 2026 | April 20, 2026 | 3d | 1,741 | — | — | derivative | Form 4 ↗ | |
| Williams John Edward | Sell F | April 17, 2026 | April 20, 2026 | 3d | 826 | $270 | $223K | Form 4 ↗ | ||
| Williams John Edward | Option / conversion M | April 17, 2026 | April 20, 2026 | 3d | 1,741 | — | — | Form 4 ↗ | ||
| McCarthy Michelle M | Option / conversion M | April 15, 2026 | April 16, 2026 | 1d | 1,736 | — | — | derivative | Form 4 ↗ | |
| McCarthy Michelle M | Option / conversion M | April 15, 2026 | April 16, 2026 | 1d | 1,107 | — | — | derivative | Form 4 ↗ | |
| McCarthy Michelle M | Option / conversion M | April 15, 2026 | April 16, 2026 | 1d | 968 | — | — | derivative | Form 4 ↗ | |
| McCarthy Michelle M | Other A | April 15, 2026 | April 16, 2026 | 1d | 1,673 | — | — | derivative | Form 4 ↗ | |
| McCarthy Michelle M | Sell F | April 15, 2026 | April 16, 2026 | 1d | 1,375 | $274 | $377K | Form 4 ↗ | ||
| McCarthy Michelle M | Option / conversion M | April 15, 2026 | April 16, 2026 | 1d | 1,736 | — | — | Form 4 ↗ | ||
| McCarthy Michelle M | Option / conversion M | April 15, 2026 | April 16, 2026 | 1d | 1,107 | — | — | Form 4 ↗ | ||
| McCarthy Michelle M | Option / conversion M | April 15, 2026 | April 16, 2026 | 1d | 968 | — | — | Form 4 ↗ | ||
| Moloney Jacqueline F | Sell S | March 12, 2026 | March 13, 2026 | 1d | 340 | $214 | $73K | Form 4 ↗ | ||
| Taranto Eric Robert | Sell S | March 6, 2026 | March 9, 2026 | 3d | 4,568 | $221 | $1.0M | Form 4 ↗ | ||
| Mora Elizabeth | Sell S | March 2, 2026 | March 3, 2026 | 1d | 300 | $239 | $72K | 10b5-1 plan | Form 4 ↗ | |
| Schreiner James Alan | Sell S | February 24, 2026 | February 25, 2026 | 1d | 4,100 | $255 | $1.0M | Form 4 ↗ | ||
| COLELLA GERALD G | Sell S | February 24, 2026 | February 24, 2026 | 0d | 10,000 | $254 | $2.5M | indirect | Form 4 ↗ | |
| COLELLA GERALD G | Sell S | February 20, 2026 | February 24, 2026 | 4d | 10,000 | $253 | $2.5M | indirect | Form 4 ↗ | |
| CANNONE PETER III | Sell S | February 20, 2026 | February 23, 2026 | 3d | 1,250 | $258 | $323K | Form 4 ↗ | ||
| Taranto Eric Robert | Sell S | February 20, 2026 | February 23, 2026 | 3d | 1,453 | $248 | $360K | Form 4 ↗ | ||
| Henry David Philip | Sell S | February 20, 2026 | February 23, 2026 | 3d | 2,000 | $262 | $523K | Form 4 ↗ | ||
| McCarthy Michelle M | Sell S | February 20, 2026 | February 23, 2026 | 3d | 816 | $250 | $204K | Form 4 ↗ | ||
| McCarthy Michelle M | Sell S | February 20, 2026 | February 23, 2026 | 3d | 650 | $250 | $162K | Form 4 ↗ | ||
| Moloney Jacqueline F | Sell S | February 20, 2026 | February 23, 2026 | 3d | 829 | $248 | $205K | Form 4 ↗ | ||
| Williams John Edward | Sell S | February 20, 2026 | February 23, 2026 | 3d | 2,043 | $256 | $524K | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Sell S | February 20, 2026 | February 23, 2026 | 3d | 4,254 | $250 | $1.1M | Form 4 ↗ | ||
| Lee John Tseng-Chung | Sell S | February 20, 2026 | February 23, 2026 | 3d | 1,890 | $260 | $491K | Form 4 ↗ | ||
| Lee John Tseng-Chung | Sell S | February 20, 2026 | February 23, 2026 | 3d | 1,988 | $258 | $513K | Form 4 ↗ | ||
| Lee John Tseng-Chung | Sell S | February 20, 2026 | February 23, 2026 | 3d | 12,812 | $257 | $3.3M | Form 4 ↗ | ||
| Lee John Tseng-Chung | Sell S | February 20, 2026 | February 23, 2026 | 3d | 13,310 | $256 | $3.4M | Form 4 ↗ | ||
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,303 | — | — | derivative | Form 4 ↗ | |
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,167 | — | — | derivative | Form 4 ↗ | |
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 976 | — | — | derivative | Form 4 ↗ | |
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 348 | — | — | derivative | Form 4 ↗ | |
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 914 | — | — | derivative | Form 4 ↗ | |
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,764 | — | — | derivative | Form 4 ↗ | |
| Taranto Eric Robert | Other A | February 17, 2026 | February 18, 2026 | 1d | 1,759 | — | — | derivative | Form 4 ↗ | |
| Taranto Eric Robert | Sell F | February 17, 2026 | February 18, 2026 | 1d | 2,712 | $261 | $707K | Form 4 ↗ | ||
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,303 | — | — | Form 4 ↗ | ||
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,167 | — | — | Form 4 ↗ | ||
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 976 | — | — | Form 4 ↗ | ||
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 348 | — | — | Form 4 ↗ | ||
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 914 | — | — | Form 4 ↗ | ||
| Taranto Eric Robert | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,764 | — | — | Form 4 ↗ | ||
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,054 | — | — | derivative | Form 4 ↗ | |
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,841 | — | — | derivative | Form 4 ↗ | |
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,278 | — | — | derivative | Form 4 ↗ | |
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 456 | — | — | derivative | Form 4 ↗ | |
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,247 | — | — | derivative | Form 4 ↗ | |
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,406 | — | — | derivative | Form 4 ↗ | |
| Henry David Philip | Other A | February 17, 2026 | February 18, 2026 | 1d | 2,567 | — | — | derivative | Form 4 ↗ | |
| Henry David Philip | Sell F | February 17, 2026 | February 18, 2026 | 1d | 4,097 | $261 | $1.1M | Form 4 ↗ | ||
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,054 | — | — | Form 4 ↗ | ||
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,841 | — | — | Form 4 ↗ | ||
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,278 | — | — | Form 4 ↗ | ||
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 456 | — | — | Form 4 ↗ | ||
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,247 | — | — | Form 4 ↗ | ||
| Henry David Philip | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,406 | — | — | Form 4 ↗ | ||
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,944 | — | — | derivative | Form 4 ↗ | |
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,741 | — | — | derivative | Form 4 ↗ | |
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,211 | — | — | derivative | Form 4 ↗ | |
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 432 | — | — | derivative | Form 4 ↗ | |
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,330 | — | — | derivative | Form 4 ↗ | |
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,567 | — | — | derivative | Form 4 ↗ | |
| Schreiner James Alan | Other A | February 17, 2026 | February 18, 2026 | 1d | 2,377 | — | — | derivative | Form 4 ↗ | |
| Schreiner James Alan | Sell F | February 17, 2026 | February 18, 2026 | 1d | 4,344 | $261 | $1.1M | Form 4 ↗ | ||
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,944 | — | — | Form 4 ↗ | ||
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,741 | — | — | Form 4 ↗ | ||
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,211 | — | — | Form 4 ↗ | ||
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 432 | — | — | Form 4 ↗ | ||
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,330 | — | — | Form 4 ↗ | ||
| Schreiner James Alan | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,567 | — | — | Form 4 ↗ | ||
| Williams John Edward | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,106 | — | — | derivative | Form 4 ↗ | |
| Williams John Edward | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 991 | — | — | derivative | Form 4 ↗ | |
| Williams John Edward | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 841 | — | — | derivative | Form 4 ↗ | |
| Williams John Edward | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 300 | — | — | derivative | Form 4 ↗ | |
| Williams John Edward | Other A | February 17, 2026 | February 18, 2026 | 1d | 1,474 | — | — | derivative | Form 4 ↗ | |
| Williams John Edward | Sell F | February 17, 2026 | February 18, 2026 | 1d | 1,195 | $261 | $312K | Form 4 ↗ | ||
| Williams John Edward | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,106 | — | — | Form 4 ↗ | ||
| Williams John Edward | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 991 | — | — | Form 4 ↗ | ||
| Williams John Edward | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 841 | — | — | Form 4 ↗ | ||
| Williams John Edward | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 300 | — | — | Form 4 ↗ | ||
| Mayampurath Ramakumar | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,702 | — | — | derivative | Form 4 ↗ | |
| Mayampurath Ramakumar | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,958 | — | — | derivative | Form 4 ↗ | |
| Mayampurath Ramakumar | Other A | February 17, 2026 | February 18, 2026 | 1d | 4,279 | — | — | derivative | Form 4 ↗ | |
| Mayampurath Ramakumar | Sell F | February 17, 2026 | February 18, 2026 | 1d | 2,516 | $261 | $656K | Form 4 ↗ | ||
| Mayampurath Ramakumar | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,702 | — | — | Form 4 ↗ | ||
| Mayampurath Ramakumar | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,958 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,493 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,336 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,576 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 563 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,788 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 3,451 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Other A | February 17, 2026 | February 18, 2026 | 1d | 3,328 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Sell F | February 17, 2026 | February 18, 2026 | 1d | 5,318 | $261 | $1.4M | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,493 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 2,336 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,576 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 563 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 1,788 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 3,451 | — | — | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 12,091 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 16,989 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 7,208 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 3,859 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 7,654 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 22,088 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Other A | February 17, 2026 | February 18, 2026 | 1d | 15,593 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Sell F | February 17, 2026 | February 18, 2026 | 1d | 32,548 | $261 | $8.5M | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 12,091 | — | — | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 16,989 | — | — | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 7,208 | — | — | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 3,859 | — | — | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 7,654 | — | — | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | February 17, 2026 | February 18, 2026 | 1d | 22,088 | — | — | Form 4 ↗ | ||
| Taranto Eric Robert | Other A | February 8, 2026 | February 9, 2026 | 1d | 3,504 | — | — | derivative | Form 4 ↗ | |
| Henry David Philip | Other A | February 8, 2026 | February 9, 2026 | 1d | 5,522 | — | — | derivative | Form 4 ↗ | |
| Schreiner James Alan | Other A | February 8, 2026 | February 9, 2026 | 1d | 5,227 | — | — | derivative | Form 4 ↗ | |
| Williams John Edward | Other A | February 8, 2026 | February 9, 2026 | 1d | 2,973 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Other A | February 8, 2026 | February 9, 2026 | 1d | 7,009 | — | — | derivative | Form 4 ↗ | |
| Mayampurath Ramakumar | Other A | February 8, 2026 | February 9, 2026 | 1d | 8,878 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Other A | February 8, 2026 | February 9, 2026 | 1d | 50,972 | — | — | derivative | Form 4 ↗ | |
| Mora Elizabeth | Sell S | December 2, 2025 | December 3, 2025 | 1d | 300 | $159 | $48K | 10b5-1 plan | Form 4 ↗ | |
| Mayampurath Ramakumar | Option / conversion M | November 17, 2025 | November 18, 2025 | 1d | 8,295 | — | — | derivative | Form 4 ↗ | |
| Mayampurath Ramakumar | Sell F | November 17, 2025 | November 18, 2025 | 1d | 2,628 | $143 | $375K | Form 4 ↗ | ||
| Mayampurath Ramakumar | Option / conversion M | November 17, 2025 | November 18, 2025 | 1d | 8,295 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 341 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 144 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 82 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 52 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 158 | — | — | derivative | Form 4 ↗ | |
| Burke Kathleen Flaherty | Sell F | October 31, 2025 | November 4, 2025 | 4d | 777 | $144 | $112K | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 341 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 144 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 82 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 52 | — | — | Form 4 ↗ | ||
| Burke Kathleen Flaherty | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 158 | — | — | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 1,651 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 352 | — | — | derivative | Form 4 ↗ | |
| Lee John Tseng-Chung | Sell F | October 31, 2025 | November 4, 2025 | 4d | 2,003 | $144 | $288K | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 1,651 | — | — | Form 4 ↗ | ||
| Lee John Tseng-Chung | Option / conversion M | October 31, 2025 | November 4, 2025 | 4d | 352 | — | — | Form 4 ↗ | ||
| Schreiner James Alan | Sell S | October 22, 2025 | October 23, 2025 | 1d | 711 | $139 | $99K | 10b5-1 plan | Form 4 ↗ | |
| Moloney Jacqueline F | Sell S | October 1, 2025 | October 2, 2025 | 1d | 300 | $122 | $37K | 10b5-1 plan | Form 4 ↗ |
Congressional trades
| Filer | Side | Trade date | Disclosed | Lag | Shares | Price | Value | Flags | Source | Share |
|---|---|---|---|---|---|---|---|---|---|---|
| Lisa C. McClain | Sell | October 31, 2025 | November 21, 2025 | 21d | — | — | $1,001–$15K | spouse | House PTR ↗ | |
| Lisa C. McClain | Buy | October 30, 2025 | November 21, 2025 | 22d | — | — | $1,001–$15K | spouse | House PTR ↗ | |
| Lisa C. McClain | Sell | October 30, 2025 | November 21, 2025 | 22d | — | — | $1,001–$15K | spouse | House PTR ↗ |
Related stocks
Tickers traded by the same people who traded MKSI, by number of filers in common. It shows overlap in public filings and nothing else.
- UTHR United Therapeutics Corporation - Common Stock 1 filer in common
- DELL Dell Technologies Inc. Class C Common Stock 1 filer in common
- STX Seagate Technology Holdings PLC - Ordinary Shares 1 filer in common
- UBER Uber Technologies, Inc. Common Stock 1 filer in common
- DDOG Datadog, Inc. - Class A Common Stock 1 filer in common
- ANET Arista Networks, Inc. Common Stock 1 filer in common
- META Meta Platforms, Inc. - Class A Common Stock 1 filer in common
- ACI Albertsons Companies, Inc. Class A Common Stock 1 filer in common
Guides for this page
- What is SEC Form 4? Who files: officers, directors and owners of more than 10% of a class of the company's shares.
- Form 4 transaction codes P = purchase. S = sale. These are the two market trades.
- Insider buying vs insider selling Selling outweighs buying by a wide margin in normal times.
- How to read a congressional trade report Owner tells you whose asset it was: the member, the spouse, a dependent child, or held jointly.
- Why congressional trade amounts are ranges There are ten ranges; the lowest is $1,001–$15,000 and the highest is over $50,000,000.
Sources and method
| Source | Filings | Rows | First filed | Newest filed | Read the originals |
|---|---|---|---|---|---|
| House Clerk, periodic transaction reports | 1 | 3 | November 21, 2025 | November 21, 2025 | House Clerk search |
| SEC EDGAR, Form 4 | 61 | 178 | October 2, 2025 | September 2, 2026 | Form 4 list on EDGAR |
Site built October 22, 2026. Every row in the tables above links to its own filing. To quote a figure, use the Cite button at the top of the page; see how to cite and reuse.
Insider rows are Form 4 filings for this issuer from SEC EDGAR; congressional rows are periodic transaction reports parsed from the House Clerk and the Senate eFD. Values use the reported price for Form 4 and the disclosed range for Congress. See methodology and corrections.
Not investment advice. Disclosures are shown as filed and may lag the trade or be amended. No recommendation is made or implied.