Form 4 for MKSI MKS INC
Accepted 2026-02-18 00:00:00 ET · period of report 2026-02-17 · accession 0001049502-26-000016 · SEC index · Original document
Summary rows
Aggregated the way they appear in lists: one row per insider, transaction code and security table.
| X | Filed | Traded | Ticker | Insider | Title | Type | Price | Qty | Owned | ΔOwn | Value |
|---|---|---|---|---|---|---|---|---|---|---|---|
| DM | 2026-02-18 | 2026-02-17 | MKSI | Lee John Tseng-Chung | Pres, CEO, Dir | M - OptEx | — | +69.9K | 205.2K | +52% | — |
| D | 2026-02-18 | 2026-02-17 | MKSI | Lee John Tseng-Chung | Pres, CEO, Dir | F - Tax | $260.74 | -32.5K | 184.7K | -15% | -$8.49M |
| DM | 2026-02-18 | 2026-02-17 | MKSI | Lee John Tseng-Chung | Pres, CEO, Dir | M - OptEx | — | -69.9K | 125.0K | -36% | — |
| D | 2026-02-18 | 2026-02-17 | MKSI | Lee John Tseng-Chung | Pres, CEO, Dir | A - Grant | — | +15.6K | 154.7K | +11% | — |
Purchase Sale Sale after option exercise All abbreviations
Every reported transaction
| # | Table | Security | Date | Code | A/D | Shares | Price | Owned after | Own | Exercise / expiry | Underlying | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Common | Common Stock | 2026-02-17 | M | A | 7,653.60 | — | 177,096.85 | D | — | — | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. |
| 2 | Common | Common Stock | 2026-02-17 | M | A | 22,088.09 | — | 169,443.25 | D | — | — | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. |
| 3 | Common | Common Stock | 2026-02-17 | M | A | 3,859.12 | — | 180,955.97 | D | — | — | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. |
| 4 | Common | Common Stock | 2026-02-17 | M | A | 7,208 | — | 188,163.97 | D | — | — | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. |
| 5 | Common | Common Stock | 2026-02-17 | F | D | 32,548.31 | $260.74 | 184,696.11 | D | — | — | |
| 6 | Common | Common Stock | 2026-02-17 | M | A | 12,091 | — | 217,244.41 | D | — | — | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. |
| 7 | Common | Common Stock | 2026-02-17 | M | A | 16,989.44 | — | 205,153.41 | D | — | — | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. |
| 8 | Derivative | Restricted Stock Unit | 2026-02-17 | M | D | 7,208 | — | 113,908.56 | D | — · — to — | 7,208 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F7) These RSUs vest in three equal annual installments commencing on February 15, 2025, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day. |
| 9 | Derivative | Restricted Stock Unit | 2026-02-17 | M | D | 12,091 | — | 84,828.12 | D | — · — to — | 12,091 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F9) These RSUs vest in three equal annual installments commencing on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day. |
| 10 | Derivative | Restricted Stock Unit | 2026-02-17 | M | D | 16,989.44 | — | 96,919.12 | D | — · — to — | 16,989.44 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F8) These RSUs were subject to performance criteria, the achievement of which was determined on February 8, 2026, and thereafter vest in three equal annual installments beginning on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day. |
| 11 | Derivative | Restricted Stock Unit | 2026-02-17 | M | D | 3,859.12 | — | 121,116.56 | D | — · — to — | 3,859.12 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F6) These RSUs were subject to performance criteria, the achievement of which was determined on February 10, 2025, and thereafter vest in three equal annual installments beginning on February 15, 2025, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day. |
| 12 | Derivative | Restricted Stock Unit | 2026-02-17 | A | A | 15,592.91 | — | 154,717.37 | D | — · — to — | 15,592.91 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F3) These RSUs vest in three equal annual installments commencing on February 15, 2027, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day. |
| 13 | Derivative | Restricted Stock Unit | 2026-02-17 | M | D | 22,088.09 | — | 132,629.28 | D | — · — to — | 22,088.09 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F4) These RSUs were subject to performance criteria, the achievement of which was determined on February 5, 2024, and thereafter vest in three equal annual installments beginning on February 15, 2024, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day. |
| 14 | Derivative | Restricted Stock Unit | 2026-02-17 | M | D | 7,653.60 | — | 124,975.68 | D | — · — to — | 7,653.60 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F5) These RSUs vest in three equal annual installments commencing on February 15, 2024, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day. |