Every Form 4 that MKS Inc. (MKSI) has filed with the SEC in the last 12 months is listed below, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A Form 4 covers the transactions officers, directors and large holders report, so if you follow MKSI and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full MKSI filings page.
MKS Inc. executive vice president and chief operating officer James Alan Schreiner reported a grant of performance-based restricted stock units. On February 8, 2026, he was awarded 5,226.759 RSUs, each representing the right to receive one share of MKS Inc. common stock.
These RSUs vest in three equal annual installments beginning on February 15, 2026, with vesting moving to the next business day if that date is not a business day. Following this grant, Schreiner beneficially owns 18,244.899 derivative securities in the form of RSUs held directly.
MKS Inc. executive John Edward Williams, EVP & GM, PSD, received an award of 2,973.357 performance-based restricted stock units (RSUs) on February 8, 2026. Each RSU represents the right to receive one share of MKS common stock.
The performance-based RSUs vest in three equal annual installments beginning on February 15, 2026, with vesting in later years occurring on February 15 or the next business day. After this grant, Williams beneficially owns 10,317.107 derivative securities related to MKS common stock.
MKS Inc. executive Kathleen Flaherty Burke, EVP, GC & Secretary, reported an equity award on a Form 4. On February 8, 2026, she was granted 7,008.628 restricted stock units (RSUs), each representing one share of MKS common stock. These performance-based RSUs vest in three equal annual installments beginning on February 15, 2026, with vesting on the next business day if that date is not a business day. After this grant, she directly holds 24,007.365 derivative securities in the form of RSUs.
MKS Inc. EVP & CFO Mayampurath Ramakumar received 8,877.596 restricted stock units (RSUs) on February 8, 2026, as reported on a Form 4. Each RSU represents the contingent right to receive one share of MKS common stock.
The RSUs were tied to performance criteria that were determined to be achieved on February 8, 2026. They vest in three equal annual installments beginning on February 15, 2026, with vesting moving to the next business day if February 15 is not a business day. Following this award, Ramakumar beneficially owns 25,279.99 derivative securities directly.
MKS Inc. President and CEO Lee John Tseng-Chung reported a grant of 50,971.84 restricted stock units on February 8, 2026. Each RSU represents the right to receive one share of MKS Inc. common stock. After this award, he beneficially owns 139,124.462 derivative securities linked to common stock.
The RSUs were tied to performance criteria that were determined on February 8, 2026. They vest in three equal annual installments beginning on February 15, 2026, with vesting moving to the next business day if February 15 is not a business day in any vesting year.
MKS Inc. executive reports RSU vesting and related share withholding. The company’s EVP & CFO reported the vesting of 8,295 restricted stock units on common stock of MKS Inc. on 11/17/2025, each RSU representing the right to receive one share of common stock.
Of these shares, 2,628 were withheld by MKS Inc. at a price of $142.74 per share to cover tax withholding obligations, leaving 5,667 shares of common stock beneficially owned directly after the transaction. Following this activity, the executive also reports 16,402.394 restricted stock units beneficially owned, which continue to represent future rights to receive common shares as they vest in scheduled installments.
MKS Inc. (MKSI) reported insider equity activity. On 10/31/2025, the company’s EVP, GC & Secretary converted restricted stock units into common stock, acquiring 158 shares, 52 shares, 82 shares, 144 shares, and 341 shares through code “M” transactions, each RSU representing one share.
To cover FICA taxes, 777 shares were withheld in a code “F” transaction at $143.71 per share. Following these transactions, the reporting person directly beneficially owned 51,074.509 shares of common stock. Derivative holdings listed after the activity show 16,998.737 RSUs remaining.
MKS Inc. (MKSI) reported insider activity by its President & CEO and Director on 10/31/2025. The filing shows RSU settlements and a related tax transaction. The executive converted RSUs into common stock under code M, acquiring 352 shares and 1,651 shares. To cover FICA taxes, 2,003 shares were disposed under code F at $143.71 per share.
Following these transactions, the executive directly owned 147,269.5227 shares. Each RSU represents the right to receive one common share. The company notes that portions of the 2024 and 2025 RSU awards were accelerated to satisfy FICA taxes.