MKSI
MKS INC · Manufacturing · Market cap $14.6B
Insiders sold $5.5M net in the last 90 days ·5 sellers, 0 buyers· 5 of 6 sales under Rule 10b5-1 plans· latest Form 4 filed Sep 2, 2026
Insider Buying
$0
reported purchases (SEC code P)
Insider Selling
$43.5M
reported sales (SEC code S)
Unique Insiders
13
in the rolling window
Latest filing
Sep 2, 2026
Mora Elizabeth
MKS INC (MKSI) has 52 SEC Form 4 filings (113 transaction rows) in the rolling window, disclosed by 13 distinct insiders. Most recent filing: Sep 2, 2026.
Inside the rolling window, 13 insiders at MKS INC reported no open-market purchases and 34 open-market sales totaling $43.5M. The most active filer is Director Mora Elizabeth with 4 filings. Insiders have net sold $26.1M over the trailing 6 months. The most recent open-market filing is a sale of 300 shares by Director Mora Elizabeth, dated Sep 1, 2026, worth $75K.
- Industry:Hardware, Equipment & Parts
- CEO:Tseng Chung Lee
- Employees:10,200
- HQ:Andover, MA, US
- IPO:1999-03-30
| Source | |||||||
|---|---|---|---|---|---|---|---|
Mora ElizabethFirst in 3 months | Director | Sale | 300 | $75K | Sep 2 | -14.0% | SEC ↗ |
| President & CEO | Sale | 10,000 | $3.0M | Aug 17 | -32.6% | SEC ↗ | |
Williams John EdwardFirst in 5 months | EVP & GM, PSD | Sale | 457 | $132K | Aug 4 | -32.6% | SEC ↗ |
| EVP & COO | Sale | 3,500 | $1.2M | Jun 16 | -41.0% | SEC ↗ | |
Schreiner James AlanFirst in 4 months | EVP & COO | Sale | 781 | $248K | Jun 11 | -37.4% | SEC ↗ |
McCarthy Michelle MFirst in 4 months | SVP & Chief Accounting Officer | Sale | 2,434 | $767K | Jun 8 | -30.8% | SEC ↗ |
| EVP, Global Str Mktg & GM, MSD | Sale | 6,000 | $1.9M | Jun 2 | -34.8% | SEC ↗ | |
Mora ElizabethFirst in 3 months | Director | Sale | 300 | $95K | Jun 2 | -34.8% | SEC ↗ |
COLELLA GERALD GFirst in 3 months | Director | Sale | 20,000 | $6.7M | May 28 | — | SEC ↗ |
Donahue Joseph BFirst filing | Director | Sale | 2,100 | $689K | May 28 | — | SEC ↗ |
Henry David PhilipFirst in 3 months | EVP, Global Str Mktg & GM, MSD | Sale | 2,500 | $826K | May 27 | — | SEC ↗ |
Lee John Tseng-ChungFirst in 3 months | President & CEO | Sale | 10,000 | $3.2M | May 26 | — | SEC ↗ |
Mayampurath RamakumarFirst filing | EVP & CFO | Sale | 8,810 | $2.8M | May 26 | — | SEC ↗ |
| Director | Sale | 1,350 | $410K | May 19 | — | SEC ↗ | |
| Director | Sale | 1,000 | $312K | May 15 | — | SEC ↗ | |
| Director | Sale | 1,400 | $447K | May 14 | — | SEC ↗ | |
| EVP, GC & Secretary | Sale | 4,355 | $1.4M | May 12 | — | SEC ↗ | |
| EVP & GM, VSD | Sale | 2,848.522 | $911K | May 12 | — | SEC ↗ | |
| Director | Sale | 340.107 | $73K | Mar 13 | — | SEC ↗ | |
| EVP & GM, VSD | Sale | 4,567.879 | $1.0M | Mar 9 | — | SEC ↗ | |
Mora ElizabethFirst in 3 months | Director | Sale | 300 | $72K | Mar 3 | — | SEC ↗ |
Schreiner James AlanFirst in 4 months | EVP & COO | Sale | 4,100 | $1.0M | Feb 25 | — | SEC ↗ |
COLELLA GERALD GFirst filing | Director | Sale | 10,000 | $2.5M | Feb 24 | — | SEC ↗ |
COLELLA GERALD GFirst filing | Director | Sale | 10,000 | $2.5M | Feb 24 | — | SEC ↗ |
Lee John Tseng-ChungFirst filing | President & CEO | Sale | 30,000 | $7.7M | Feb 23 | — | SEC ↗ |
Earnings: last 7 quarters
Congress trading MKSI 5 all-time
- RRep. Lisa C. McClainPurchase$1,001 - $15,0002025-08-04
- RSen. Thomas Hawley TubervilleOther$1,001 - $15,0002023-04-03
- RSen. Thomas Hawley TubervilleOther$1,001 - $15,0002023-04-03
- RSen. Thomas Hawley TubervilleOther$1,001 - $15,0002023-04-03
- RSen. Thomas Hawley TubervillePurchase$1,001 - $15,0002022-03-30
STOCK Act disclosures are filed up to 45 days after the trade. Amount is a disclosed range, not an exact figure.
Frequently asked questions
How many SEC Form 4 insider filings does MKSI have?
MKS INC (MKSI) has 52 SEC Form 4 filings (113 transaction rows) in the rolling 365-day window, disclosed by 13 distinct insiders. Most recent filing: Sep 2, 2026.
When was the most recent SEC Form 4 filing for MKSI?
The most recent Form 4 filing for MKSI on Tracefour is dated Sep 2, 2026.
Who is the most active insider at MKSI?
The most active SEC Form 4 filer at MKSI in the rolling window is Director Mora Elizabeth, with 4 filings.
What is the net insider flow at MKSI over the last 6 months?
Over the trailing 180 days, insiders at MKSI have net sold $26.1M based on SEC Form 4 disclosures.
What is the total insider buy and sell value at MKSI in the current window?
Inside the rolling window, insiders at MKSI bought $0 and sold $43.5M based on SEC Form 4 filings.
Can I get alerts for MKSI insider trading?
Yes. Tracefour sends a free email when a new SEC Form 4 purchase or sale is filed at MKS INC (MKSI). Alerts are set per company from the page itself, there is no paid tier, and each email links to the original filing on SEC EDGAR.
Related companies
MKS INC is in the Manufacturing sector.