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 (MKSI) director Elizabeth Mora reported selling 300 shares of common stock on September 1, 2026 in an open-market transaction at $250.96 per share. After this sale, she directly held 18,845.353 shares of MKS INC common stock. The transaction was effected under a Rule 10b5-1 trading plan adopted on February 23, 2026.
MKS INC (symbol: MKSI) is the issuer of record for a Form 4 filing submitted to the SEC.
MKS INC executive John Tseng-Chung Lee, President & CEO, reported selling 10,000 shares of Common Stock on 2026-08-14 at $302.01 per share in an open-market or private transaction. Following the sale, he directly holds 134,776.2667 shares. The sale was executed under a Rule 10b5-1 trading plan adopted on February 20, 2026.
MKS Inc executive John Edward Williams, EVP & GM, PSD, reported selling 457 shares of Common Stock on August 3, 2026 at $288.31 per share in a sale described as an open market or private transaction. Following this trade, he directly held 4,097.844 shares. The sale was effected pursuant to a Rule 10b5-1 trading plan adopted on March 5, 2026.
MKS Inc EVP & COO James Alan Schreiner reported selling a total of 3,500 shares of MKS Inc common stock on June 12, 2026 in three open-market transactions. The shares were sold at weighted average prices of $347.00, $346.41 and $345.52 per share. After these sales, Schreiner directly holds 19,201.121 MKS Inc common shares.
MKS Inc executive James Alan Schreiner, the company’s EVP & COO, reported an open-market sale of 781 shares of Common Stock on June 10, 2026 at an average price of $317.42 per share.
After this transaction, Schreiner directly holds 22,701.121 shares of MKS Inc common stock. The sale was executed under a pre-arranged Rule 10b5-1 trading plan that he adopted on March 10, 2026, indicating the trade was scheduled in advance rather than timed discretionarily.
MKS Inc senior vice president and chief accounting officer Michelle M. McCarthy sold 2,434 shares of common stock in an open-market transaction at $315.23 per share. After the sale, she directly holds 1.5490 shares. The transaction was carried out under a pre-arranged Rule 10b5-1 trading plan adopted on March 5, 2026, indicating it was scheduled in advance.
MKS Inc executive Henry David Philip reported an open-market sale of company stock. On June 1, 2026, he sold 6,000 shares of MKS Inc Common Stock in an open-market transaction at a weighted average price of $314.4305 per share. Following this sale, he directly owns 10,421.527 shares of MKS Inc Common Stock. The filing notes the trade was executed in multiple lots at prices ranging from $314.2425 to $314.955, with the reported price representing the weighted average.
MKS Inc director Elizabeth Mora reported an open-market sale of 300 shares of MKS Inc Common Stock at $318.02 per share on June 1, 2026. The sale was executed under a pre-arranged Rule 10b5-1 trading plan adopted on February 23, 2026. After this transaction, she directly holds 19,145.353 shares of MKS Inc Common Stock.
MKS Inc director Joseph B. Donahue reported an open‑market sale of 2,100 shares of Common Stock on May 27, 2026 at a weighted average price of $327.954 per share.
The sale was executed in multiple trades between $327.90 and $328.21. After this transaction, Donahue directly holds about 10,032.704 MKS Inc common shares.
MKS Inc director Gerald G. Colella reported a net sale of 20,000 shares of MKS Inc common stock through an affiliated trust. On May 27, 2026, The Gerald G. Colella 2019 Trust executed seven open‑market sales at prices around $330 per share, leaving the trust holding 39,553 shares afterward.
Separately, Colella is shown with 8,998.886 shares held directly as a position entry rather than a new trade. A footnote states that at least one of the sales was made under a pre‑arranged Rule 10b5‑1 trading plan adopted on February 24, 2026, indicating the transactions were scheduled in advance.
MKS Inc executive Henry David Philip reported an open-market sale of 2,500 shares of Common Stock at $330.50 per share. After the transaction, he directly holds 16,341.368 shares. The sale was carried out under a pre-arranged Rule 10b5-1 trading plan adopted on February 24, 2026.
MKS INC EVP & CFO Mayampurath Ramakumar sold 8,810 shares of Common Stock in an open-market transaction. The sale took place on May 22, 2026 at an average price of $315.4800 per share.
After this transaction, he directly owned 1.1390 shares of MKS INC common stock, according to the filing. The sale was carried out under a pre-arranged Rule 10b5-1 trading plan adopted on February 20, 2026, indicating it was scheduled in advance rather than timed discretionarily.
MKS Inc President & CEO John Tseng-Chung Lee sold 10,000 shares of MKS Inc common stock in an open-market transaction at a price of $315.48 per share. The sale was made under a pre-arranged Rule 10b5-1 trading plan adopted by the executive.
After this transaction, Lee still directly holds about 144,696 shares of MKS Inc common stock, indicating he retains a substantial equity stake in the company despite the sale.
MKS Inc director Peter Cannone III reported an open-market sale of 1,350 shares of Common Stock on May 18, 2026 at a price of $303.4001 per share. After this transaction, he directly holds 7,794.039 shares, indicating he retains a meaningful ongoing equity stake in the company.
MKS INC director Jacqueline F. Moloney reported an open-market sale of 1,000 shares of Common Stock. The shares were sold at an average price of $312.1969 per share. After this transaction, she directly holds 8,775.156 MKS INC shares, indicating she retains a substantial ongoing equity position.
MKS INC director Jacqueline F. Moloney reported an open-market sale of company stock. On May 13, 2026, she sold 1,400 shares of Common Stock at an average price of $318.99 per share.
After this transaction, she directly holds 9,775.156 shares of MKS INC common stock. This filing reflects a director monetizing a portion of her existing equity position while retaining a substantial remaining stake.
MKS INC executive Eric Robert Taranto, EVP & GM, VSD, reported an open-market sale of common stock. On May 11, 2026, he sold 2,848.522 shares at a weighted average price of $319.930 per share in multiple trades between $319.930 and $320.345. After this transaction, he directly holds 12,596.2394 shares of MKS common stock.
Moloney Jacqueline F reported acquisition or exercise transactions in this Form 4 filing.
MKS Inc director Jacqueline F. Moloney received an equity award in the form of restricted stock units (RSUs). She was granted 781.959 shares of common stock-equivalent RSUs at no cash cost, increasing her direct holdings to 11,175.156 shares of common stock.
The RSUs will fully vest on the day before the first annual meeting of shareholders following the grant date, or, if no such meeting occurs within 13 months, on the 13‑month anniversary of the grant. Each RSU represents the right to receive one share of MKS Inc common stock upon vesting.
JABRE WISSAM G reported acquisition or exercise transactions in this Form 4 filing.
MKS Inc director Wissam G. Jabre received an equity award of 781.959 restricted stock units, each tied to one share of common stock at no cost per unit. These units become fully vested on the day before the first annual shareholder meeting following the grant date, or on the 13‑month anniversary if no meeting occurs within that period. After this grant, he directly holds 5,269.935 shares or equivalent units.
Mora Elizabeth reported acquisition or exercise transactions in this Form 4 filing.
MKS Inc director Elizabeth Mora reported an equity award of restricted stock units. On May 11, 2026, she received 781.959 restricted stock units of MKS Inc common stock as a grant, not a market purchase or sale, at a stated price of $0.00 per unit.
The units become fully vested on the day before the first annual meeting of shareholders following the grant date, or on the 13‑month anniversary of the grant if no such meeting occurs within that period. Each unit represents the right to receive one share of MKS Inc common stock, and after this award she holds 19,445.353 shares directly.
MKS INC executive Kathleen Flaherty Burke reported an open-market sale of 4,355 shares of Common Stock. The transaction occurred on May 11, 2026 at a weighted average price of $319.935 per share, executed in multiple trades between $319.715 and $320.670.
After this sale, Burke directly holds 49,439.485 shares of MKS INC common stock. The filing notes she can provide full trade details, including the number of shares and prices for each individual execution, upon request.
Donahue Joseph B reported acquisition or exercise transactions in this Form 4 filing.
MKS Inc. director Joseph B. Donahue received a grant of 781.959 restricted stock units of common stock as compensation. These units vest in full on the day before the first annual meeting of shareholders after the grant date, or on the 13‑month anniversary if no meeting occurs. After this award, Donahue directly holds a total of 12,132.704 shares of MKS common stock, assuming settlement of vested units in shares. Each restricted stock unit represents the right to receive one share of MKS Inc. common stock when it vests, so this filing reflects equity-based compensation rather than an open-market purchase.
CANNONE PETER III reported acquisition or exercise transactions in this Form 4 filing.
MKS Inc director Peter Cannone III reported an equity award on Form 4. He received 781.959 restricted stock units, each representing the right to receive one share of MKS common stock. These units vest in full just before the first annual shareholder meeting following the grant. After this award, he directly holds 9,144.039 shares of common stock.
Batra Raj reported acquisition or exercise transactions in this Form 4 filing.
MKS Inc director Raj Batra received a grant of 781.959 restricted stock units (RSUs) of common stock. Each RSU represents the right to receive one MKS share. These RSUs become fully vested on the day before the first annual shareholder meeting after the grant date (or after 13 months if no meeting is held), bringing his direct holdings to 16,227.298 shares.
COLELLA GERALD G reported acquisition or exercise transactions in this Form 4 filing.
MKS Inc director Gerald G. Colella reported a compensation-related equity grant. On May 11, 2026, he received 781.959 shares of common stock at $0.00 per share as a grant of restricted stock units that vest before the next annual shareholder meeting. After this award, he holds 8,998.886 common shares directly and 40,017 shares indirectly through The Gerald G. Colella 2019 Trust.
MKS Inc EVP & GM, PSD John Edward Williams reported routine equity compensation activity involving restricted stock units (RSUs). On April 17, 2026, RSUs representing 1,740.714 shares of common stock were converted into common shares, reflecting the vesting of previously granted awards.
To cover tax withholding obligations from this RSU vesting, 825.969 common shares were withheld by MKS Inc, which the company notes does not represent a discretionary trade by Williams. Following these transactions, he directly holds 4,554.844 shares of MKS Inc common stock.
MKS Inc. senior vice president and chief accounting officer Michelle M. McCarthy reported equity compensation activity involving restricted stock units (RSUs) and related common stock on April 15, 2026. She received a grant of 1,672.862 RSUs, each representing a contingent right to one share of MKS common stock, which will vest in three equal annual installments beginning on April 15, 2027.
On the same date, RSUs in amounts of 968, 1,107, and 1,736 units were exercised or converted into the same number of common shares as part of earlier awards that vest in three annual installments beginning on April 15, 2025 and April 15, 2026. To cover tax withholding obligations triggered by these vestings, 1,375.451 common shares were withheld by MKS Inc. at a price of $274.15 per share, which the filing notes was not a discretionary trade. Following these transactions, McCarthy directly held 2,435.549 shares of common stock and 7,388.160 RSUs.
MKS INC director Jacqueline F. Moloney reported an open-market sale of 340.107 shares of common stock on March 12, 2026 at a weighted average price of $213.7717 per share. The trades were executed in multiple transactions between $213.7716 and $214.015 per share.
After this sale, Moloney directly owns 10,393.197 shares of MKS INC common stock. The filing notes that detailed trade-by-trade pricing and share data are available upon request.
MKS INC executive Eric Robert Taranto, EVP & GM, VSD, reported an open-market sale of 4,567.879 shares of common stock on March 6, 2026 at a weighted average price of $220.522 per share. After this sale, he directly holds 15,444.7614 shares of MKS INC common stock.
The sale was executed in multiple trades at prices ranging from $220.3701 to $220.780, with the reported price representing the weighted average across those trades.
MKS INC director Elizabeth Mora reported an open-market sale of company stock. She sold 300 shares of common stock at a price of $239.44 per share. After this transaction, she continued to hold 18,663.394 shares of MKS INC common stock directly.
The sale was executed under a pre-arranged Rule 10b5-1 trading plan that she adopted on February 19, 2025, indicating the transaction was scheduled in advance rather than timed discretionarily.
MKS Inc executive James Alan Schreiner, EVP & COO, reported an open-market sale of 4,100 shares of common stock at $255.00 per share on February 24, 2026. After this transaction, he directly owns 23,401.962 shares of MKS Inc common stock.
MKS Inc. director Gerald G. Colella reported open-market sales of company common stock held indirectly through The Gerald G. Colella 2019 Trust. The trust sold 10,000 shares on February 20, 2026 at a weighted average price of $252.8999 per share and another 10,000 shares on February 24, 2026 at a weighted average price of $253.9675 per share. After these sales, the trust held 40,017 shares, while Colella also held 8,216.927 shares directly.
MKS INC director CANNONE PETER III sold 1,250.0000 shares of common stock in an open-market transaction on February 20, 2026 at a weighted average price of $258.0596 per share. After the sale, he directly owned 8,362.0800 shares. The sale was executed in multiple trades between $258.040 and $258.285 per share.
MKS INC executive Eric Robert Taranto, EVP & GM, VSD, reported an open-market sale of 1,452.73 shares of common stock at $247.55 per share on February 20, 2026. After this transaction, he directly owned 20,012.6404 common shares.
MKS INC executive Henry David Philip reported an open-market sale of company stock. On this Form 4, he sold 2,000 shares of MKS INC common stock at a price of $261.5601 per share. After this transaction, he directly owns 18,841.368 shares of MKS INC common stock.
MKS INC vice president and chief accounting officer Michelle M. McCarthy reported selling a total of 1,466 shares of common stock in open-market transactions on February 20, 2026. The sales were executed at weighted average prices of $249.5674 and $250.3479 per share, in multiple trades within stated price ranges. Following these sales, her directly held common stock position reported in this filing was reduced to zero shares.
MKS Inc director Jacqueline F. Moloney reported an open-market sale of company stock. She sold 829 shares of MKS Inc common stock at a price of $247.55 per share on February 20, 2026. After this transaction, she still directly owns 10,733.304 shares of MKS Inc common stock.
MKS INC executive John Edward Williams, EVP & GM, PSD, reported an open-market sale of 2,042.625 shares of common stock on February 20, 2026 at a weighted average price of $256.4075 per share. After this sale, he directly owns 3,640.099 common shares. The sale was executed in multiple trades between $256.3902 and $257.150 per share.
MKS Inc executive Kathleen Flaherty Burke, EVP, GC & Secretary, reported an open-market sale of 4,254 shares of Common Stock at $250.00 per share on February 20, 2026. After this sale, she directly owns 53,794.485 shares of MKS Inc common stock.
MKS Inc. President & CEO Lee John Tseng-Chung reported selling a total of 30,000 shares of common stock in open-market transactions. The sales occurred on February 20, 2026 at weighted average prices around $256–$260 per share across multiple trade executions.
Individual reported trades covered 13,310 shares at $256.0538, 12,812 shares at $256.9313, 1,988 shares at $257.8084, and 1,890 shares at $259.7032. After these transactions, he directly owns about 154,696.1077 shares of MKS Inc. common stock.
MKS Inc executive Eric Robert Taranto, EVP & GM, VSD, reported multiple equity compensation transactions dated February 17, 2026. He received a grant of 1758.9560 restricted stock units, each representing one share of common stock, which vest in three equal annual installments commencing on February 15, 2027.
Several prior restricted stock unit awards were exercised or converted into common stock at a share price of $0.0000, reflecting scheduled vesting under earlier grants. In connection with these vestings, 2711.7680 common shares valued at $260.7400 per share were withheld by MKS Inc to satisfy tax withholding obligations, and the filing states this did not represent a discretionary trade by Taranto.
MKS Inc executive Henry David Philip reported multiple equity compensation transactions. On February 17, 2026, he received a grant of 2,567.126 restricted stock units (RSUs) at a stated price of 0.0000 per unit.
He also exercised or converted several RSU awards into common stock, with multiple transactions coded "M" as derivative exercises or conversions. After these conversions and before tax withholding, his direct common stock holdings reached 24,938.637 shares. A separate transaction coded "F" disposed of 4,097.269 common shares at 260.7400 per share to satisfy tax withholding obligations triggered by RSU vesting, which the footnotes state was not a discretionary trade. Following the tax-related share withholding, he directly held 20,841.368 common shares. Footnotes explain that various RSU awards vest in three equal annual installments beginning on specific February 15 dates from 2024 through 2027, with each RSU representing the right to receive one share of MKS Inc common stock.
MKS Inc. EVP & COO James Alan Schreiner reported equity compensation activity on restricted stock units and common stock. He received a grant of 2,376.968 RSUs, each representing one MKS share, which vests in three equal annual installments starting on February 15, 2027. Multiple existing RSU awards were exercised or converted into common stock at no cash exercise price, reflecting previously granted time- and performance-based awards that vest in three annual installments around February 15 in 2024, 2025 and 2026. In a separate transaction, 4,343.764 common shares were disposed of at a price of $260.74 per share to satisfy tax withholding obligations triggered by RSU vesting, and this did not represent a discretionary trade by Schreiner.
MKS Inc executive John Edward Williams reported multiple equity compensation transactions. He received a grant of 1,473.720 restricted stock units on February 17, 2026. Several existing RSU awards were exercised or converted into common stock at a stated price of $0.0000 per share, increasing his direct common share holdings. In addition, 1,195.485 common shares at $260.7400 per share were disposed of to cover tax withholding obligations related to RSU vesting, which the disclosure notes was not a discretionary trade.
MKS Inc EVP & CFO Mayampurath Ramakumar reported multiple equity transactions on common stock and restricted stock units. He acquired shares through exercises and conversions of RSUs, received a new RSU award, and had shares of common stock withheld by MKS Inc to cover tax obligations from RSU vesting, which the filing states were not discretionary trades.
MKS Inc EVP, GC & Secretary Kathleen Flaherty Burke reported equity compensation activity involving restricted stock units (RSUs) and common stock. On February 17, 2026, she received a grant of 3,327.755 RSUs, each representing the contingent right to one share of MKS common stock.
On the same date, several RSU awards were exercised or converted, increasing her directly held common stock through multiple transactions labeled as derivative exercises. Following these transactions, she directly owned 63,366.283 shares of common stock and 27,335.120 RSUs.
The filing also shows a disposition of 5,317.798 shares of common stock at a price of $260.7400 per share. According to the disclosure, these shares were withheld by MKS Inc. solely to satisfy tax withholding obligations triggered by RSU vesting and do not represent a discretionary trade by the executive.
MKS Inc President & CEO John Tseng-Chung Lee reported equity compensation activity and related tax withholding. He received a grant of 15,592.911 restricted stock units, each representing the right to one MKS Inc common share. Several previously granted RSUs, including performance-based awards, were exercised and converted into common stock as they vested. To satisfy tax withholding obligations from these vestings, 32,548.307 common shares were delivered back to MKS Inc at $260.74 per share, which the company notes was not a discretionary trade.
MKS Inc. executive Eric Robert Taranto received 3,504.314 performance-based restricted stock units (RSUs) on February 8, 2026. Each RSU represents the right to receive one share of MKS common stock. After this award, he beneficially owns 12,742.601 derivative securities in the form of RSUs.
The RSUs were tied to performance criteria that were determined to be achieved on February 8, 2026. They will vest in three equal annual installments starting on February 15, 2026, or the next business day if that date is not a business day.
MKS Inc. executive Henry David Philip received a new performance-based equity award. On February 8, 2026, he was granted 5,521.949 restricted stock units (RSUs) at no cash cost, each representing one share of MKS Inc. common stock.
The achievement of performance criteria for these RSUs was determined on February 8, 2026. The units will vest in three equal annual installments starting on February 15, 2026, with vesting moving to the next business day if February 15 is not a business day. After this grant, Philip beneficially owned 18,808.107 derivative securities in the form of RSUs, held directly.