| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Williams John Edward | EVP & GM, PSD | C/O MKS INC., 2 TECH DRIVE, ANDOVER | /s/ James Kruger, attorney-in-fact | 18 Aug 2025 | 0001710173 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | MKSI | Common Stock | Options Exercise | +947 | +32% | 3,948 | 15 Aug 2025 | Direct | F1 | ||
| transaction | MKSI | Common Stock | Tax liability | $32,257 | -308 | -7.8% | $104.73 | 3,640 | 15 Aug 2025 | Direct | F2 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Underlying Class | Amount | Exercise Price | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | MKSI | Restricted Stock Unit | Options Exercise | -947 | -11% | 7,344 | 15 Aug 2025 | Common Stock | 947 | Direct | F1, F3 |
| Id | Content |
|---|---|
| F1 | Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc. |
| 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. |
| F3 | These RSUs vest in two equal annual installments commencing on August 15, 2024, provided that if, in any vesting year, August 15th is not a business day, such vesting shall occur on the next business day. |