John Edward Williams
CIK 1710173 · View on SEC EDGAR ↗
Insider
First SEC filing: May 15, 2024 · Latest: May 15, 2024
On this page
Insider at
Insider transactions
0 buys (P)
2 sells (S)
Net:
$-655,604
+ 35 non-open-market transactions below
last 12 months, based on the transactions shown below
Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted
35 other filings hidden
| Date | Ticker | Code | Shares | Price | Value | Owned after | Δ own | A/D | vs now |
|---|---|---|---|---|---|---|---|---|---|
| Aug. 3, 2026 | MKSI | S 10b5-1 | 457 | $288.31 | $131,758 | 4,098 Direct | -10.03% | Disposed | -1.0% (price as of 2026-08-19) |
| Feb. 20, 2026 | MKSI | S | 2,043 | $256.41 | $523,846 | 3,640 Direct | -35.95% | Disposed | 11.3% (price as of 2026-08-19) |
| Aug. 16, 2024 | MKSI | S | 1,800 | $118.71 | $213,678 | 13 Direct | -99.28% | Disposed | 140.4% (price as of 2026-08-19) |
P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding
Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.
Derivative holdings (Form 4 Table II)
Options, RSUs and convertible securities reported on Form 4 Table II.
| Date | Ticker | Security | Underlying | Exercise price | Expiration | Shares | A/D |
|---|---|---|---|---|---|---|---|
| April 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (1,741) | — | — | 1,741 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (1,106) | — | — | 1,106 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (991) | — | — | 991 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (841) | — | — | 841 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (300) | — | — | 300 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (1,474) | — | — | 1,474 | Acquired |
| Feb. 8, 2026 | MKSI | Restricted Stock Unit | Common Stock (2,973) | — | — | 2,973 | Acquired |
| Aug. 15, 2025 | MKSI | Restricted Stock Unit | Common Stock (947) | — | — | 947 | Disposed |
| April 17, 2025 | MKSI | Restricted Stock Unit | Common Stock (1,740) | — | — | 1,740 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (841) | — | — | 841 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (300) | — | — | 300 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (658) | — | — | 658 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (915) | — | — | 915 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (3,318) | — | — | 3,318 | Acquired |
| Feb. 10, 2025 | MKSI | Restricted Stock Unit | Common Stock (901) | — | — | 901 | Acquired |
| Aug. 15, 2024 | MKSI | Restricted Stock Unit | Common Stock (946) | — | — | 946 | Disposed |
| May 15, 2024 | MKSI | Restricted Stock Unit | Common Stock (2,524) | — | — | 2,524 | Acquired |
Exercise/conversion price is blank when not applicable (e.g. RSUs).
Initial ownership (Form 3) 5 holdings
Securities held when first becoming an insider, per SEC Form 3.
| Date | Ticker | Security | Shares | Ownership |
|---|---|---|---|---|
| May 15, 2024 | MKSI | Common Stock | 1,174 | Direct |
| May 15, 2024 | MKSI | Restricted Stock Unit→ Common Stock (915) | 915 | Direct |
| May 15, 2024 | MKSI | Restricted Stock Unit→ Common Stock (658) | 658 | Direct |
| May 15, 2024 | MKSI | Restricted Stock Unit→ Common Stock (1,893) | 1,893 | Direct |
| May 15, 2024 | MKSI | Restricted Stock Unit→ Common Stock (3,481) | 3,481 | Direct |