Form 4 for MKSI MKS INC
Accepted 2026-04-16 15:29:01 ET · period of report 2026-04-15 · accession 0001049502-26-000059 · 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 | 2026-04-16 15:29 | 2026-04-15 | MKSI | McCarthy Michelle M | SVP, CAO | M - OptEx | — | +3,811 | 3,811 | New | — |
| D | 2026-04-16 15:29 | 2026-04-15 | MKSI | McCarthy Michelle M | SVP, CAO | F - Tax | $274.15 | -1,375 | 2,436 | -36% | -$377.1K |
| D | 2026-04-16 15:29 | 2026-04-15 | MKSI | McCarthy Michelle M | SVP, CAO | A - Grant | — | +1,673 | 11.2K | +18% | — |
| DM | 2026-04-16 15:29 | 2026-04-15 | MKSI | McCarthy Michelle M | SVP, CAO | M - OptEx | — | -3,811 | 7,388 | -34% | — |
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 | 2026-04-15 | M | A | 968 | — | 968 | 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 | 2026-04-15 | M | A | 1,107 | — | 2,075 | 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 | 2026-04-15 | M | A | 1,736 | — | 3,811 | 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 | 2026-04-15 | F | D | 1,375.45 | $274.15 | 2,435.55 | D | — | — | (F2) These shares were withheld by MKS Inc. to satisfy the tax withholding obligations triggered by the vesting of RSUs and do not represent a discretionary trade by the reporting person. |
| 5 | Derivative | Restricted Stock Unit | 2026-04-15 | A | A | 1,672.86 | — | 11,199.16 | D | — · — to — | 1,672.86 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (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 April 15, 2027, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day. (F3) These RSUs vest in three equal annual installments commencing on April 15, 2027, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day. |
| 6 | Derivative | Restricted Stock Unit | 2026-04-15 | M | D | 968 | — | 10,231.16 | D | — · — to — | 968 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F4) These RSUs vest in three equal annual installments commencing on April 15, 2025, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day. (F4) These RSUs vest in three equal annual installments commencing on April 15, 2025, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day. |
| 7 | Derivative | Restricted Stock Unit | 2026-04-15 | M | D | 1,107 | — | 9,124.16 | D | — · — to — | 1,107 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (F4) These RSUs vest in three equal annual installments commencing on April 15, 2025, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day. (F4) These RSUs vest in three equal annual installments commencing on April 15, 2025, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day. |
| 8 | Derivative | Restricted Stock Unit | 2026-04-15 | M | D | 1,736 | — | 7,388.16 | D | — · — to — | 1,736 Common Stock | (F1) Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. (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 April 15, 2026, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day. (F5) These RSUs vest in three equal annual installments commencing on April 15, 2026, provided that if, in any vesting year, April 15th is not a business day, such vesting shall occur on the next business day. |