Company profile
Mks Inc Insider Trading
MKSIEvery SEC Form 4 insider trading filing for Mks Inc (MKSI) since April 2023 — open-market buys and sells by directors and officers, option exercises, and cluster activity, updated as each filing is reported to the SEC. Why 2023?
- Exchange
- Nasdaq
- Sector
- Industrial Instruments For Measurement, Display, and Control
- CIK
- 0001049502
- Filings
- 165
- Insiders
- 35
- Last filing
- 2026-09-01
Activity summary
No discretionary insider buying or selling in the last 30 days. The 1 transaction filed was made under a 10b5-1 plan, scheduled in advance rather than decided on the day.
Three year balance
Buy and sell value by quarter, Q4 23 to Q3 26. Mks Inc insiders were net sellers in every quarter shown.
Bars below the rule are sales, above are purchases. Largest quarter on the chart is $32.1M.
90 day insight
Over the last 90 days, Mks Inc insiders bought $0 across 1 transaction with no open-market sales.
- Most active insider: John Tseng-Chung Lee with 1 transaction totaling $3.0M.
- Largest single sale: $3.0M by John Tseng-Chung Lee on Aug 14, 2026.
- 100% of recent sales were pre-scheduled 10b5-1 trades — typically less informative than open-market activity.
Activity skews bullish — buys outpace sales.
Insider Transactions
Sourced from SEC EDGAR Form 4 filings. Updated hourly.
| Date | Insider | Company | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Sep 1, 2026 | Elizabeth Mora | MKSI | Sale10b5 | 300 | $250.96 | $75K |
| Aug 17, 2026 | Renee Martel Donlan | MKSI | Award | 954.044 | — | — |
| Aug 14, 2026 | John Tseng-Chung Lee | MKSI | Sale10b5 | 10,000 | $302.01 | $3.02M |
| Aug 3, 2026 | John Edward Williams | MKSI | Sale10b5 | 457 | $288.31 | $132K |
| Jun 12, 2026 | James Alan Schreiner | MKSI | Sale | 2,471 | $345.52 | $854K |
45 more transactions hidden
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Query this yourself
The same rows, over the API.
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-H "X-Api-Key: $KEY"Top insiders
By total value filed.
Institutional Ownership
Top 13F-HR holders of Mks Inc as of 2026-06-30
Data source: quarterly 13F-HR filings — institutional holders report positions within 45 days of quarter end. Joined with insider activity above — see who's loading up institutionally while insiders are trading. Full 13F-HR API →