Quick Takeaways
- MKSI - MKS INC has 21 insiders with reported activity on this page.
- Net insider value flow over the last year: -$22,723,935.
- Recent transaction rows are available for direct filing-level review.
Insider Transactions Reported by 21 Insiders of MKS INC
- Symbol
- MKSI on Nasdaq
- Location
- Andover, MA
What Changed
- Buy value: ; sell value: $22,723,935.
- Net share flow: -93,212.
Why This Matters
- This page gives a plain-language issuer insider context before you inspect transaction-level evidence.
- Use the filing links below to verify timestamps, codes, and ownership impacts directly from SEC forms.
Source Evidence
Filed on Form 4
See Original Filing
Issuer insider activity is sourced from SEC Forms 3, 4, and 5.
Insider trading overview
Last 12 monthsNet insider flow leans to selling over the last 12 months. Net value: -$22,723,935.
Buys
$0
Shares: 0
Insiders: 0
Sells
$22,723,935
Shares: 93,212
Insiders: 11
Net
-$22,723,935
Shares: -93,212
Insiders: -11
| Window (months) | Buy shares | Sell shares | Buy $ | Sell $ | Net $ |
|---|---|---|---|---|---|
| 0-3 | 0 | 82,206 | $0 | $21,396,983 | -$21,396,983 |
| 3-6 | 0 | 300 | $0 | $47,643 | -$47,643 |
| 6-9 | 0 | 7,149 | $0 | $919,110 | -$919,110 |
| 9-12 | 0 | 3,557 | $0 | $360,199 | -$360,199 |
MKS INC executives and other stock owners filed with the SEC include:
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Carlyle Group Inc. | 10%+ Owner | $713,103,113 | Mixed | 08 May 2023 | ||
| Carlyle Partners VI Cayman Holdings, L.P. | 10%+ Owner | $713,103,113 | Mixed | 08 May 2023 | ||
| John Tseng-Chung Lee | President & CEO, Director | $49,598,861 | -$7,703,242 | -13% | Mixed | 20 Feb 2026 |
| Kathleen Flaherty Burke | EVP, GC & Secretary | $17,660,232 | -$2,456,817 | -12% | Mixed | 11 May 2026 |
| Geoffrey Wild | Director | $11,838,269 | Mixed | 17 Aug 2022 | ||
| Gerald G. Colella | Director | $11,264,339 | -$5,068,674 | -31% | Median | 11 May 2026 |
| James Alan Schreiner | Evp & Coo | $7,453,018 | -$1,346,049 | -15% | Mixed | 24 Feb 2026 |
| David Philip Henry | EVP, Global Str Mktg & GM, MSD | $6,305,526 | -$1,383,120 | -18% | Mixed | 20 Feb 2026 |
| Eric Robert Taranto | Evp & Gm, Vsd | $4,987,647 | -$2,278,269 | -31% | Mixed | 11 May 2026 |
| Ramakumar Mayampurath | Evp & Cfo | $4,857,795 | Mixed | 17 Feb 2026 | ||
| Elizabeth Mora | Director | $4,468,736 | -$173,964 | -3.7% | Median | 11 May 2026 |
| Raj Batra | Director | $3,729,195 | Median | 11 May 2026 | ||
| Mark Milton Gitin | Evp & Gm, Psd | $3,328,164 | Mixed | 15 Feb 2024 | ||
| Seth H. Bagshaw | EVP, CFO & Treasurer | $3,135,791 | Mixed | 22 Feb 2024 | ||
| Joseph B. Donahue | Director | $2,788,216 | Median | 11 May 2026 | ||
| Jacqueline F. Moloney | Director | $2,739,576 | -$1,100,979 | -29% | Filing P/S | 14 May 2026 |
| Peter Cannone III | Director | $2,101,391 | -$322,575 | -13% | Median | 11 May 2026 |
| John Edward Williams | Evp & Gm, Psd | $1,614,519 | -$523,744 | -24% | Mixed | 17 Apr 2026 |
| Michelle M. Warner | Director | $1,443,294 | Mixed | 07 May 2024 | ||
| Michelle M. McCarthy | SVP & Chief Accounting Officer | $1,440,515 | -$366,503 | -20% | Mixed | 15 Apr 2026 |
| Wissam G. Jabre | Director | $1,211,083 | Median | 11 May 2026 |
Top shareholders of MKS INC (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Ownership % is shown only when it is directly reported or safely comparable across share classes.
Methodology: rows are grouped by holder and ranked by the holder's primary source value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
| Holder | Source | Role / Reporting | Ownership % | Shares | Holdings Value | 12M Net Δ | As of | Details |
|---|---|---|---|---|---|---|---|---|
| BlackRock, Inc. |
13F
13D/G
|
Company |
8.8%
from 13D/G
|
6,641,730
|
$1,526,335,861 | — | 31 Mar 2026 | |
| Invesco Ltd. |
13F
13D/G
|
Company |
6.5%
from 13D/G
|
3,721,459
|
$855,228,394 | — | 31 Mar 2026 | |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
13F
|
Vanguard Portfolio Management · Company |
5.5%
|
3,700,062
|
$850,311,248 | $0 | 31 Mar 2026 | |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
|
Vanguard Capital Management · Company |
5.2%
|
3,528,836
|
$810,961,801 | $0 | 31 Mar 2026 | |
| Carlyle Group Inc. |
3/4/5
|
10%+ Owner |
—
class O/S missing
|
6,482,732
|
$713,103,113 | — | 08 May 2023 | |
| Carlyle Partners VI Cayman Holdings, L.P. |
3/4/5
|
10%+ Owner |
—
class O/S missing
|
6,482,732
|
$713,103,113 | — | 08 May 2023 | |
| FMR LLC |
13D/G
13F
|
Company |
3.3%
|
2,243,989
|
$613,012,951 | $0 | 31 Mar 2026 | |
| PRICE T ROWE ASSOCIATES INC /MD/ |
13D/G
13F
|
T. Rowe Price Associates, Inc. · Company |
4.1%
|
2,753,871
|
$505,335,328 | -$252,359,660 | 31 Dec 2025 | |
| STATE STREET CORP |
13F
|
Company |
3%
|
2,057,732
|
$472,887,391 | — | 31 Mar 2026 | |
| Capital International Investors |
13F
13D/G
|
Company |
4.7%
from 13D/G
|
1,968,770
|
$452,443,034 | — | 31 Mar 2026 | |
| JPMORGAN CHASE & CO |
13F
|
Company |
3.1%
|
2,096,342
|
$441,217,278 | — | 31 Mar 2026 | |
| WELLINGTON MANAGEMENT GROUP LLP |
13F
|
Company |
2.7%
|
1,833,137
|
$421,273,215 | — | 31 Mar 2026 | |
| VICTORY CAPITAL MANAGEMENT INC |
13D/G
13F
|
Company |
5.6%
|
3,787,201
|
$381,446,885 | $0 | 30 Jun 2025 | |
| Point72 Asset Management, L.P. |
13F
|
Company |
2.4%
|
1,610,331
|
$370,070,167 | — | 31 Mar 2026 | |
| GEODE CAPITAL MANAGEMENT, LLC |
13F
|
Company |
2.3%
|
1,539,319
|
$353,818,861 | — | 31 Mar 2026 | |
| Aspex Management (HK) Ltd |
13F
|
Company |
2.3%
|
1,538,789
|
$353,629,000 | — | 31 Mar 2026 | |
| Neuberger Berman Group LLC |
13F
|
Company |
2.1%
|
1,433,529
|
$329,439,399 | — | 31 Mar 2026 | |
| Whale Rock Capital Management LLC |
13F
|
Company |
1.9%
|
1,306,724
|
$300,298,242 | — | 31 Mar 2026 | |
| Capital World Investors |
13F
|
Company |
1.9%
|
1,277,200
|
$293,513,332 | — | 31 Mar 2026 | |
| WESTFIELD CAPITAL MANAGEMENT CO LP |
13F
|
Company |
1.5%
|
1,046,763
|
$240,556,578 | — | 31 Mar 2026 | |
| CITADEL ADVISORS LLC |
13F
|
Company |
1.4%
|
947,032
|
$217,637,424 | — | 31 Mar 2026 | |
| MILLENNIUM MANAGEMENT LLC |
13F
|
Company |
1.3%
|
894,369
|
$205,534,940 | — | 31 Mar 2026 | |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC |
13F
|
Company |
1.3%
|
866,647
|
$199,164,147 | — | 31 Mar 2026 | |
| DIMENSIONAL FUND ADVISORS LP |
13F
|
Company |
1.2%
|
835,345
|
$191,879,336 | — | 31 Mar 2026 | |
| Bank of New York Mellon Corp |
13F
|
Company |
1.2%
|
832,150
|
$191,236,622 | — | 31 Mar 2026 | |
| PRINCIPAL FINANCIAL GROUP INC |
13F
|
Company |
0.9%
|
614,230
|
$141,162,055 | — | 31 Mar 2026 | |
| AQR CAPITAL MANAGEMENT LLC |
13F
|
Company |
0.91%
|
616,497
|
$136,862,293 | — | 31 Mar 2026 | |
| NORTHERN TRUST CORP |
13F
|
Company |
0.84%
|
569,224
|
$130,813,368 | — | 31 Mar 2026 | |
| MORGAN STANLEY |
13F
|
Company |
0.76%
|
515,063
|
$118,366,809 | — | 31 Mar 2026 | |
| SAMLYN CAPITAL, LLC |
13F
|
Company |
0.73%
|
496,685
|
$114,143,180 | — | 31 Mar 2026 | |
| FRANKLIN RESOURCES INC |
13F
|
Company |
0.7%
|
475,893
|
$109,364,969 | — | 31 Mar 2026 | |
| BANK OF AMERICA CORP /DE/ |
13F
|
Company |
0.68%
|
463,709
|
$106,564,965 | — | 31 Mar 2026 | |
| FengHe Fund Management Pte. Ltd. |
13F
|
Company |
0.67%
|
456,329
|
$104,868,967 | — | 31 Mar 2026 | |
| UBS Group AG |
13F
|
Company |
0.64%
|
432,130
|
$99,307,795 | — | 31 Mar 2026 | |
| VANGUARD FIDUCIARY TRUST CO |
13F
|
Company |
0.61%
|
417,114
|
$95,856,968 | — | 31 Mar 2026 | |
| BALYASNY ASSET MANAGEMENT L.P. |
13F
|
Company |
0.6%
|
407,395
|
$93,623,445 | — | 31 Mar 2026 | |
| ROYCE & ASSOCIATES LP |
13F
|
Company |
0.59%
|
403,670
|
$92,767,403 | — | 31 Mar 2026 | |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE |
13F
|
Company |
0.59%
|
400,319
|
$91,956,927 | — | 31 Mar 2026 | |
| Nuveen, LLC |
13F
|
Company |
0.56%
|
378,158
|
$86,904,490 | — | 31 Mar 2026 | |
| Blue Grotto Capital, LLC |
13F
|
Company |
0.55%
|
375,000
|
$86,178,750 | — | 31 Mar 2026 | |
| Contour Asset Management LLC |
13F
|
Company |
0.55%
|
374,868
|
$86,148,415 | — | 31 Mar 2026 | |
| Madison Asset Management, LLC |
13F
|
Company |
0.5%
|
338,336
|
$77,753,102 | — | 31 Mar 2026 | |
| RAYMOND JAMES FINANCIAL INC |
13F
|
Company |
0.5%
|
337,962
|
$75,834,166 | — | 31 Mar 2026 | |
| TREMBLANT CAPITAL GROUP |
13F
|
Company |
0.48%
|
329,786
|
$75,788,121 | — | 31 Mar 2026 | |
| NORDEA INVESTMENT MANAGEMENT AB |
13F
|
Company |
0.48%
|
326,308
|
$71,477,768 | — | 31 Mar 2026 | |
| TimesSquare Capital Management, LLC |
13F
|
Company |
0.42%
|
288,165
|
$66,223,199 | — | 31 Mar 2026 | |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC |
13F
|
Company |
0.42%
|
282,206
|
$64,853,761 | — | 31 Mar 2026 | |
| AMERICAN CENTURY COMPANIES INC |
13F
|
Company |
0.41%
|
280,965
|
$64,569,141 | — | 31 Mar 2026 | |
| TWO SIGMA INVESTMENTS, LP |
13F
|
Company |
0.41%
|
278,687
|
$64,045,059 | — | 31 Mar 2026 | |
| NOMURA HOLDINGS INC |
13F
|
Company |
0.4%
|
269,356
|
$61,900,702 | — | 31 Mar 2026 |
Recent Insider Transactions by Companies or Individuals for MKS INC
Showing up to 300 most recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | Value $ | * Price $ | Shares | Shares Owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Jacqueline F. Moloney | MKSI | Common Stock | Sale | -10.2% | $312,197 | $312.20 | -1,000 | 8,775 | 14 May 2026 | Direct |
| Jacqueline F. Moloney | MKSI | Common Stock | Sale | -12.5% | $446,586 | $318.99 | -1,400 | 9,775 | 13 May 2026 | Direct |
| Eric Robert Taranto | MKSI | Common Stock | Sale | -18.4% | $911,328 | $319.93 | -2,849 | 12,596 | 11 May 2026 | Direct |
| Jacqueline F. Moloney | MKSI | Common Stock | Award | 7.52% | 782 | 11,175 | 11 May 2026 | Direct | ||
| Wissam G. Jabre | MKSI | Common Stock | Award | 17.4% | 782 | 5,270 | 11 May 2026 | Direct | ||
| Elizabeth Mora | MKSI | Common Stock | Award | 4.19% | 782 | 19,445 | 11 May 2026 | Direct | ||
| Kathleen Flaherty Burke | MKSI | Common Stock | Sale | -8.1% | $1,393,317 | $319.94 | -4,355 | 49,439 | 11 May 2026 | Direct |
| Joseph B. Donahue | MKSI | Common Stock | Award | 6.89% | 782 | 12,133 | 11 May 2026 | Direct | ||
| Peter Cannone III | MKSI | Common Stock | Award | 9.35% | 782 | 9,144 | 11 May 2026 | Direct | ||
| Raj Batra | MKSI | Common Stock | Award | 5.06% | 782 | 16,227 | 11 May 2026 | Direct | ||
| Gerald G. Colella | MKSI | Common Stock | Award | 9.52% | 782 | 8,999 | 11 May 2026 | Direct | ||
| John Edward Williams | MKSI | Common Stock | Tax liability | -15.4% | -826 | 4,555 | 17 Apr 2026 | Direct | ||
| John Edward Williams | MKSI | Common Stock | Options Exercise | 47.8% | 1,741 | 5,381 | 17 Apr 2026 | Direct | ||
| John Edward Williams | MKSI | Restricted Stock Unit | Options Exercise | -20.4% | -1,741 | 6,812 | 17 Apr 2026 | Direct | ||
| Michelle M. McCarthy | MKSI | Common Stock | Tax liability | -36.1% | -1,375 | 2,436 | 15 Apr 2026 | Direct | ||
| Michelle M. McCarthy | MKSI | Common Stock | Options Exercise | 3,811 | 3,811 | 15 Apr 2026 | Direct | |||
| Michelle M. McCarthy | MKSI | Restricted Stock Unit | Options Exercise | -34% | -3,811 | 7,388 | 15 Apr 2026 | Direct | ||
| Michelle M. McCarthy | MKSI | Restricted Stock Unit | Award | 17.6% | 1,673 | 11,199 | 15 Apr 2026 | Direct | ||
| Jacqueline F. Moloney | MKSI | Common Stock | Sale | -3.17% | $72,705 | $213.77 | -340 | 10,393 | 12 Mar 2026 | Direct |
| Eric Robert Taranto | MKSI | Common Stock | Sale | -22.8% | $1,007,318 | $220.52 | -4,568 | 15,445 | 06 Mar 2026 | Direct |
| Elizabeth Mora | MKSI | Common Stock | Sale | -1.58% | $71,832 | $239.44 | -300 | 18,663 | 02 Mar 2026 | Direct |
| James Alan Schreiner | MKSI | Common Stock | Sale | -14.9% | $1,045,500 | $255.00 | -4,100 | 23,402 | 24 Feb 2026 | Direct |
| Gerald G. Colella | MKSI | Common Stock | Sale | -20% | $2,539,675 | $253.97 | -10,000 | 40,017 | 24 Feb 2026 | By The Gerald G. Colella 2019 Trust |
| Gerald G. Colella | MKSI | Common Stock | Sale | -16.7% | $2,528,999 | $252.90 | -10,000 | 50,017 | 20 Feb 2026 | By The Gerald G. Colella 2019 Trust |
| Peter Cannone III | MKSI | Common Stock | Sale | -13% | $322,574 | $258.06 | -1,250 | 8,362 | 20 Feb 2026 | Direct |
| Eric Robert Taranto | MKSI | Common Stock | Sale | -6.77% | $359,623 | $247.55 | -1,453 | 20,013 | 20 Feb 2026 | Direct |
| David Philip Henry | MKSI | Common Stock | Sale | -9.6% | $523,120 | $261.56 | -2,000 | 18,841 | 20 Feb 2026 | Direct |
| Michelle M. McCarthy | MKSI | Common Stock | Sale | -100% | $366,503 | $250.00 | -1,466 | 0 | 20 Feb 2026 | Direct |
| Jacqueline F. Moloney | MKSI | Common Stock | Sale | -7.17% | $205,219 | $247.55 | -829 | 10,733 | 20 Feb 2026 | Direct |
| John Edward Williams | MKSI | Common Stock | Sale | -35.9% | $523,744 | $256.41 | -2,043 | 3,640 | 20 Feb 2026 | Direct |
| Kathleen Flaherty Burke | MKSI | Common Stock | Sale | -7.33% | $1,063,500 | $250.00 | -4,254 | 53,794 | 20 Feb 2026 | Direct |
| John Tseng-Chung Lee | MKSI | Common Stock | Sale | -16.2% | $7,703,242 | $256.77 | -30,000 | 154,696 | 20 Feb 2026 | Direct |
| Eric Robert Taranto | MKSI | Common Stock | Tax liability | -11.2% | -2,712 | 21,465 | 17 Feb 2026 | Direct | ||
| Eric Robert Taranto | MKSI | Common Stock | Options Exercise | 36.6% | 6,473 | 24,177 | 17 Feb 2026 | Direct | ||
| Eric Robert Taranto | MKSI | Restricted Stock Unit | Options Exercise | -44.6% | -6,473 | 8,029 | 17 Feb 2026 | Direct | ||
| Eric Robert Taranto | MKSI | Restricted Stock Unit | Award | 13.8% | 1,759 | 14,502 | 17 Feb 2026 | Direct | ||
| David Philip Henry | MKSI | Common Stock | Tax liability | -16.4% | -4,097 | 20,841 | 17 Feb 2026 | Direct | ||
| David Philip Henry | MKSI | Common Stock | Options Exercise | 59.3% | 9,282 | 24,939 | 17 Feb 2026 | Direct | ||
| David Philip Henry | MKSI | Restricted Stock Unit | Options Exercise | -43.4% | -9,282 | 12,093 | 17 Feb 2026 | Direct | ||
| David Philip Henry | MKSI | Restricted Stock Unit | Award | 13.6% | 2,567 | 21,375 | 17 Feb 2026 | Direct | ||
| James Alan Schreiner | MKSI | Common Stock | Tax liability | -13.6% | -4,344 | 27,502 | 17 Feb 2026 | Direct | ||
| James Alan Schreiner | MKSI | Common Stock | Options Exercise | 40.8% | 9,225 | 31,846 | 17 Feb 2026 | Direct | ||
| James Alan Schreiner | MKSI | Restricted Stock Unit | Options Exercise | -44.7% | -9,225 | 11,396 | 17 Feb 2026 | Direct | ||
| James Alan Schreiner | MKSI | Restricted Stock Unit | Award | 13% | 2,377 | 20,622 | 17 Feb 2026 | Direct | ||
| John Edward Williams | MKSI | Common Stock | Tax liability | -17.4% | -1,195 | 5,683 | 17 Feb 2026 | Direct | ||
| John Edward Williams | MKSI | Common Stock | Options Exercise | 89% | 3,238 | 6,878 | 17 Feb 2026 | Direct | ||
| John Edward Williams | MKSI | Restricted Stock Unit | Options Exercise | -27.5% | -3,238 | 8,553 | 17 Feb 2026 | Direct | ||
| John Edward Williams | MKSI | Restricted Stock Unit | Award | 14.3% | 1,474 | 11,791 | 17 Feb 2026 | Direct | ||
| Ramakumar Mayampurath | MKSI | Common Stock | Tax liability | -22.2% | -2,516 | 8,811 | 17 Feb 2026 | Direct | ||
| Ramakumar Mayampurath | MKSI | Common Stock | Options Exercise | 99.9% | 5,660 | 11,327 | 17 Feb 2026 | Direct |
* An asterisk sign (*) next to the price indicates that the price is likely invalid.