John Tseng-Chung Lee insider trades: Mks (MKSI) stock buys and sales
Trades on the price chart
Daily close, with an arrow on each day they bought or sold
Companies
Where John reports to the SEC
Open-market buys and sales
26 trades reported on SEC Form 4, newest first
| Date | Stock | Type | Shares | Price | Value | Holding | Reported |
|---|---|---|---|---|---|---|---|
| Aug 14, 2026 | MKSI | ↓ Sell | 10,000 | $302.01 | $3.0M | Direct | Aug 17, 2026 (3d) |
| May 22, 2026 | MKSI | ↓ Sell | 10,000 | $315.48 | $3.2M | Direct | May 26, 2026 (4d) |
| Feb 20, 2026 | MKSI | ↓ Sell | 30,000 | $256.77 | $7.7M | Direct | Feb 23, 2026 (3d) |
| Feb 20, 2018 | MKSI | ↓ Sell | 13,432 | $115.38 | $1.5M | Direct | Feb 21, 2018 (1d) |
| Nov 13, 2017 | MKSI | ↓ Sell | 2,113 | $104.02 | $220K | Direct | Nov 14, 2017 (1d) |
| Feb 22, 2017 | MKSI | ↓ Sell | 14,734 | $67.99 | $1.0M | Direct | Feb 23, 2017 (1d) |
| Aug 10, 2016 | MKSI | ↓ Sell | 9,955 | $46.36 | $462K | Direct | Aug 11, 2016 (1d) |
| Feb 26, 2016 | MKSI | ↓ Sell | 994 | $32.70 | $33K | Direct | Feb 29, 2016 (3d) |
| Feb 17, 2016 | MKSI | ↓ Sell | 1,371 | $33.26 | $46K | Direct | Feb 18, 2016 (1d) |
| Feb 11, 2016 | MKSI | ↓ Sell | 1,435 | $31.96 | $46K | Direct | Feb 12, 2016 (1d) |
| May 14, 2015 | MKSI | ↓ Sell | 10,747 | $36.36 | $391K | Direct | May 15, 2015 (1d) |
| Jun 13, 2014 | MKSI | ↓ Sell | 9,128 | $29.55 | $270K | Direct | Jun 16, 2014 (3d) |
| Nov 29, 2013 | MKSI | ↑ Buy | 443 | $23.96 | $11K | Direct | Dec 4, 2013 (5d) |
| May 31, 2013 | MKSI | ↑ Buy | 520 | $20.42 | $11K | Direct | Jun 4, 2013 (4d) |
| Mar 14, 2013 | MKSI | ↓ Sell | 8,160 | $27.64 | $226K | Direct | Mar 15, 2013 (1d) |
| Nov 30, 2012 | MKSI | ↑ Buy | 479 | $20.61 | $10K | Direct | Dec 5, 2012 (5d) |
| Aug 6, 2012 | MKSI | ↓ Sell | 2,868 | $26.67 | $76K | Direct | Aug 7, 2012 (1d) |
| Mar 9, 2012 | MKSI | ↓ Sell | 8,595 | $29.13 | $250K | Direct | Mar 12, 2012 (3d) |
| Nov 8, 2011 | MKSI | ↓ Sell | 3,140 | $27.56 | $87K | Direct | Nov 14, 2011 (6d) |
| Mar 17, 2011 | MKSI | ↓ Sell | 4,449 | $29.31 | $130K | Direct | Mar 18, 2011 (1d) |
| Mar 8, 2011 | MKSI | ↓ Sell | 6,129 | $31.82 | $195K | Direct | Mar 9, 2011 (1d) |
| Nov 5, 2010 | MKSI | ↓ Sell | 2,374 | $21.60 | $51K | Direct | Nov 9, 2010 (4d) |
| Apr 26, 2010 | MKSI | ↓ Sell | 6,623 | $24.15 | $160K | Direct | Apr 27, 2010 (1d) |
| Feb 11, 2010 | MKSI | ↓ Sell | 2,409 | $18.74 | $45K | Direct | Feb 16, 2010 (5d) |
| Jul 28, 2009 | MKSI | ↓ Sell | 6,187 | $19.13 | $118K | Direct | Jul 30, 2009 (2d) |
| Mar 2, 2009 | MKSI | ↓ Sell | 1,574 | $11.89 | $19K | Direct | Mar 4, 2009 (2d) |
Each row is one filing's trades in one stock, summed. Shares and prices are as filed, before any later stock split.
Other MKSI insiders
Open-market trades in the last 12 months
About John Tseng-Chung Lee's insider trades
John Tseng-Chung Lee is President & CEO at Mks (MKSI). Since Mar 2, 2009, John has reported 3 open-market purchases worth $31K and 23 sales worth $19.3M on SEC Form 4. In the last 12 months: 3 sales ($13.9M).
Their filings also include option exercises (50 filings), shares withheld for taxes (42 filings), grants and awards (40 filings), other transactions (8 filings). These aren't open-market trades and aren't counted above.
How to read insider trades
Officers, directors and owners of more than 10% of a company must report trades in its stock on SEC Form 4, usually within two business days. Purchases with their own money are the stronger signal: insiders sell for many reasons (taxes, diversification, a house), but buy for one. See every MKSI insider trade, the latest insider trades across the market, or cluster buys, when several insiders buy the same stock within days.