MKSI Insider Trading

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Insider Trading History
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About

Insider Ownership Percentage: 0.57%

Insider Buying (Last 12 Months): $0.00

Insider Selling (Last 12 Months): $35,736,077.21

MKS Insider Trading History Chart

MKS Share Price & Price History

^$406.37

+0.30 (1.20%)

As of 06/18/2026 04:00 PM ET

Days: 30 | 90 | 365

MKS Insider Trading History

Transaction Date	Insider Name	Title	Buy/Sell	Number of Shares	Average Share Price	Total Transaction	Shares Held After Transaction
6/5/2026	Michelle M Mccarthy	CAO	Sell	2,434	$315.23	$767,269.82	2
5/27/2026	Gerald G Colella	Director	Sell	20,000	$333.40	$6,668,000.00	20,017
5/27/2026	Joseph B Donahue	Director	Sell	2,100	$327.95	$688,695.00	10,033
5/26/2026	David Philip Henry	EVP	Sell	2,500	$330.50	$826,250.00	16,341
5/22/2026	John Tseng-Chung Lee	CEO	Sell	10,000	$315.48	$3,154,800.00	144,696
5/22/2026	Ramakumar Mayampurath	CFO	Sell	8,810	$315.48	$2,779,378.80	1
5/18/2026	Peter J. Cannone, III	Director	Sell	1,350	$303.40	$409,590.00	7,794
5/14/2026	Jacqueline F. Moloney	Director	Sell	1,000	$312.20	$312,200.00	8,775
5/13/2026	Jacqueline F. Moloney	Director	Sell	1,400	$318.99	$446,586.00	9,775
5/11/2026	Kathleen Flaherty Burke	EVP	Sell	4,355	$319.94	$1,393,338.70	49,439
3/12/2026	Jacqueline F. Moloney	Director	Sell	340	$213.77	$72,681.80	10,393
3/6/2026	Eric Robert Taranto	EVP	Sell	4,568	$220.52	$1,007,335.36	15,445
3/2/2026	Elizabeth Mora	Director	Sell	300	$239.44	$71,832.00	18,663
2/24/2026	Gerald G Colella	Director	Sell	10,000	$253.97	$2,539,700.00	40,017
2/20/2026	David Philip Henry	EVP	Sell	2,000	$261.56	$523,120.00	18,841
2/20/2026	Eric Robert Taranto	EVP	Sell	1,453	$247.55	$359,690.15	20,013
2/20/2026	Gerald G Colella	Director	Sell	10,000	$252.90	$2,529,000.00	50,017
2/20/2026	Jacqueline F. Moloney	Director	Sell	829	$247.55	$205,218.95	10,733
2/20/2026	John Edward Williams	EVP	Sell	2,043	$256.41	$523,845.63	3,640
2/20/2026	John Tseng-Chung Lee	CEO	Sell	30,000	$256.77	$7,703,100.00	154,696
2/20/2026	Kathleen Flaherty Burke	EVP	Sell	4,254	$250.00	$1,063,500.00	53,794
2/20/2026	Michelle M Mccarthy	CAO	Sell	1,466	$250.00	$366,500.00
2/20/2026	Peter J. Cannone, III	Director	Sell	1,250	$258.06	$322,575.00	8,362
12/2/2025	Elizabeth Mora	Director	Sell	300	$158.81	$47,643.00	18,963
10/1/2025	Jacqueline F. Moloney	Director	Sell	300	$122.14	$36,642.00	11,562
9/18/2025	David Philip Henry	EVP	Sell	5,000	$130.00	$650,000.00	15,571
9/2/2025	Elizabeth Mora	Director	Sell	300	$99.85	$29,955.00	19,263
8/1/2025	Jacqueline F. Moloney	Director	Sell	300	$92.10	$27,630.00	11,862
7/3/2025	David Philip Henry	EVP	Sell	2,000	$105.00	$210,000.00	20,571
3/3/2025	Elizabeth Mora	Director	Sell	275	$92.46	$25,426.50	17,384
2/18/2025	Gerard G. Colella	Director	Sell	8,000	$104.53	$836,240.00	60,017
12/10/2024	Jacqueline F. Moloney	Director	Sell	300	$114.80	$34,440.00	9,983
12/2/2024	Elizabeth Mora	Director	Sell	275	$113.41	$31,187.75	17,659
10/1/2024	Jacqueline F. Moloney	Director	Sell	250	$108.90	$27,225.00	10,283
9/3/2024	Elizabeth Mora	Director	Sell	275	$115.97	$31,891.75	17,934
8/16/2024	John Edward Williams	EVP	Sell	1,800	$118.71	$213,678.00	13
8/1/2024	Jacqueline F. Moloney	Director	Sell	250	$123.46	$30,865.00	10,533
6/3/2024	Elizabeth Mora	Director	Sell	275	$129.41	$35,587.75	18,209
4/1/2024	Elizabeth Mora	Director	Sell	250	$133.00	$33,250.00	16,862
3/1/2024	Jacqueline F. Moloney	Director	Sell	250	$122.89	$30,722.50	9,161
3/1/2024	Kathleen Flaherty Burke	EVP	Sell	7,411	$122.89	$910,737.79	42,999
2/22/2024	Seth H. Bagshaw	CFO	Sell	32,865	$123.28	$4,051,597.20	1
2/9/2024	Gerard G. Colella	Director	Sell	10,000	$120.00	$1,200,000.00	68,017
1/22/2024	Gerard G. Colella	Director	Sell	10,000	$110.00	$1,100,000.00	78,017
1/2/2024	Elizabeth Mora	Director	Sell	250	$100.90	$25,225.00	17,112
12/1/2023	Jacqueline F. Moloney	Director	Sell	250	$82.23	$20,557.50	11,328
11/7/2023	David Philip Henry	EVP	Buy	2,500	$68.34	$170,850.00	11,073
10/2/2023	Elizabeth Mora	Director	Sell	250	$87.15	$21,787.50	17,362
9/6/2023	Seth H. Bagshaw	CFO	Sell	25,000	$97.30	$2,432,500.00	20,547
8/31/2023	Gerard G. Colella	Director	Sell	10,000	$100.01	$1,000,100.00	88,017
8/28/2023	Jacqueline F. Moloney	Director	Sell	250	$95.25	$23,812.50	11,578
8/7/2023	Kathleen Flaherty Burke	EVP	Sell	11,563	$101.23	$1,170,522.49	42,738
7/3/2023	Elizabeth Mora	Director	Sell	250	$108.49	$27,122.50	17,612

SEC Filings (Institutional Ownership Changes) for MKS (NASDAQ:MKSI)

99.79% of MKS stock is owned by institutions. Institutional ownership can be a sign of analyst confidence in the fundamentals of the stock.

Institutional Buying and Selling by Quarter

MKS Institutional Trading History

Reporting Date	Hedge Fund	Shares Held	Market Value	% of Portfolio	Quarterly Change in Shares	Ownership in Company
6/18/2026	Pacer Advisors Inc.	10,479	$2.41M	0.0%	-2.0%	0.016%
6/16/2026	Empowered Funds LLC	3,402	$0.78M	0.0%	-8.0%	0.005%
6/3/2026	Parallel Advisors LLC	1,058	$0.24M	0.0%	+10.2%	0.002%
5/22/2026	Segall Bryant & Hamill LLC	39,434	$9.06M	0.1%	N/A	0.058%
5/19/2026	Front Row Advisors LLC	8,105	$1.86M	0.6%	+2.5%	0.012%
5/19/2026	Western Wealth Management LLC	400	$92K	0.0%	N/A	0.001%
5/19/2026	Edgestream Partners L.P.	42,701	$9.81M	0.3%	-27.5%	0.063%
5/19/2026	Anson Funds Management LP	16,500	$3.79M	0.3%	N/A	0.024%
5/19/2026	Janus Henderson Group PLC	30,370	$6.98M	0.0%	+4.5%	0.045%
5/19/2026	Bull Harbor Capital LLC	1,051	$0.24M	0.1%	N/A	0.002%
5/19/2026	Arkadios Wealth Advisors	1,311	$0.30M	0.0%	N/A	0.002%
5/18/2026	EverSource Wealth Advisors LLC	1,120	$0.26M	0.0%	+48.3%	0.002%
5/18/2026	California State Teachers Retirement System	77,734	$17.86M	0.0%	+21.7%	0.115%
5/18/2026	Royal Bank of Canada	153,003	$35.16M	0.0%	-88.4%	0.227%
5/18/2026	Empowered Funds LLC	3,402	$0.78M	0.0%	-8.0%	0.005%
5/16/2026	Infrastructure Capital Advisors LLC	1,750	$0.40M	0.0%	-51.0%	0.003%
5/16/2026	Maverick Capital Ltd.	7,286	$1.67M	0.0%	N/A	0.011%
5/16/2026	Quantinno Capital Management LP	259,749	$59.69M	0.1%	+12.5%	0.385%
5/16/2026	Daventry Group LP	36,556	$8.40M	9.6%	N/A	0.054%
5/16/2026	SummitTX Capital L.P.	160,909	$36.98M	1.2%	-21.8%	0.238%
5/15/2026	Dean Capital Management	9,144	$2.10M	0.9%	-24.4%	0.014%
5/15/2026	Delta Global Management LP	151,117	$34.73M	2.8%	-53.8%	0.224%
5/15/2026	Absolute Gestao de Investimentos Ltda.	890	$0.21M	0.0%	N/A	0.001%
5/15/2026	OMERS ADMINISTRATION Corp	1,200	$0.28M	0.0%	N/A	0.002%
5/14/2026	Renaissance Technologies LLC	103,603	$23.81M	0.0%	N/A	0.153%
5/14/2026	Gabelli Funds LLC	47,058	$10.81M	0.1%	+0.1%	0.070%
5/14/2026	Public Employees Retirement System of Ohio	37,486	$8.62M	0.0%	-32.2%	0.056%
5/14/2026	Compound Planning Inc.	1,085	$0.25M	0.0%	N/A	0.002%
5/14/2026	Modern Wealth Management LLC	961	$0.23M	0.0%	N/A	0.001%
5/14/2026	Caxton Associates LLP	8,017	$1.84M	0.0%	+2.6%	0.012%
5/14/2026	Systematic Financial Management LP	242,063	$55.63M	1.3%	-8.6%	0.358%
5/14/2026	Lido Advisors LLC	3,929	$0.90M	0.0%	-34.6%	0.006%
5/14/2026	Globeflex Capital L P	34,954	$8.03M	1.2%	-3.7%	0.052%
5/14/2026	State of Wyoming	3,660	$0.84M	0.1%	-18.0%	0.005%
5/13/2026	Cetera Investment Advisers	26,512	$6.09M	0.0%	-2.0%	0.039%
5/13/2026	Bowie Capital Management LLC	64,593	$14.84M	0.5%	N/A	0.096%
5/13/2026	First Trust Advisors LP	52,056	$11.96M	0.0%	-1.7%	0.077%
5/8/2026	PNC Financial Services Group Inc.	9,444	$2.17M	0.0%	-5.6%	0.014%
5/8/2026	Madison Asset Management LLC	338,336	$77.75M	1.0%	-63.3%	0.503%
5/7/2026	Leith Wheeler Investment Counsel Ltd.	37,234	$8.56M	0.7%	-23.2%	0.055%
5/7/2026	Earned Wealth Advisors LLC	1,385	$0.32M	0.0%	+8.6%	0.002%
5/7/2026	Meeder Advisory Services Inc.	5,101	$1.17M	0.0%	+8.0%	0.008%
5/7/2026	WCM Investment Management LLC	12,120	$2.55M	0.0%	-34.7%	0.018%
5/7/2026	Dimensional Fund Advisors LP	835,345	$191.88M	0.0%	-25.2%	1.241%
5/7/2026	Parallel Advisors LLC	1,058	$0.24M	0.0%	+10.2%	0.002%
5/7/2026	KBC Group NV	26,137	$6.01M	0.0%	+1,181.9%	0.039%
5/7/2026	SEB Asset Management AB	52,000	$11.95M	0.1%	N/A	0.077%
5/7/2026	Swiss National Bank	132,900	$30.54M	0.0%	+0.3%	0.197%
5/7/2026	ANB Bank	1,288	$0.30M	0.1%	N/A	0.002%
5/6/2026	Dorsey Wright & Associates	5,784	$1.33M	0.2%	N/A	0.009%
5/6/2026	California Public Employees Retirement System	123,288	$28.33M	0.0%	+7.8%	0.183%
5/6/2026	Watershed Asset Management L.L.C.	1,827	$0.42M	0.4%	-37.0%	0.003%
5/6/2026	Kera Capital Partners Inc.	2,433	$0.56M	0.1%	+6.2%	0.004%
5/6/2026	Angeles Wealth Management LLC	875	$0.20M	0.0%	N/A	0.001%
5/6/2026	Bessemer Group Inc.	117,851	$27.08M	0.0%	-25.4%	0.175%
5/5/2026	Sanctuary Advisors LLC	7,342	$1.69M	0.0%	-19.1%	0.011%
5/4/2026	Empirical Financial Services LLC d.b.a. Empirical Wealth Management	2,165	$0.50M	0.0%	N/A	0.003%
5/4/2026	Archer Investment Corp	5,066	$1.16M	0.2%	+27.6%	0.008%
5/4/2026	State of Michigan Retirement System	16,140	$3.71M	0.0%	+1.9%	0.024%
5/4/2026	Principal Financial Group Inc.	614,230	$141.16M	0.1%	-19.8%	0.912%
5/4/2026	Chicago Partners Investment Group LLC	3,384	$0.78M	0.0%	+57.1%	0.005%
5/4/2026	Teachers Retirement System of The State of Kentucky	32,572	$7.49M	0.1%	-14.1%	0.048%
5/1/2026	Fifth Third Bancorp	19,294	$4.43M	0.0%	+3,011.9%	0.029%
5/1/2026	Sequoia Financial Advisors LLC	1,445	$0.33M	0.0%	-29.0%	0.002%
4/30/2026	Equitable Trust Co.	7,224	$1.66M	0.1%	-38.5%	0.011%
4/30/2026	Hsbc Holdings PLC	2,398	$0.55M	0.0%	-74.5%	0.004%
4/30/2026	Mitsubishi UFJ Morgan Stanley Securities Co. Ltd.	1,388	$0.32M	0.8%	N/A	0.002%
4/30/2026	Oregon Public Employees Retirement Fund	13,766	$3.16M	0.0%	+2.8%	0.020%
4/30/2026	Quantum Portfolio Management LLC	1,394	$0.32M	0.0%	-51.7%	0.002%
4/29/2026	Childress Capital Advisors LLC	872	$0.20M	0.0%	N/A	0.001%
4/29/2026	Resonant Capital Advisors LLC	1,250	$0.29M	0.0%	N/A	0.002%
4/29/2026	Burney Co.	1,360	$0.31M	0.0%	+7.1%	0.002%
4/28/2026	Whittier Trust Co. of Nevada Inc.	145	$34K	0.0%	-32.9%	0.000%
4/28/2026	Hudson Edge Investment Partners Inc.	3,813	$0.88M	0.1%	-39.6%	0.006%
4/28/2026	QRG Capital Management Inc.	3,836	$0.88M	0.0%	-14.8%	0.006%
4/27/2026	HB Wealth Management LLC	2,034	$0.47M	0.0%	N/A	0.003%
4/27/2026	Counterpoint Mutual Funds LLC	2,430	$0.56M	0.1%	+25.1%	0.004%
4/27/2026	World Investment Advisors	1,226	$0.28M	0.0%	-7.1%	0.002%
4/27/2026	New York State Teachers Retirement System	63,109	$14.50M	0.0%	-3.3%	0.094%
4/27/2026	Sierra Summit Advisors LLC	4,879	$1.12M	0.2%	N/A	0.007%
4/27/2026	Private Advisor Group LLC	3,144	$0.72M	0.0%	-24.1%	0.005%
4/27/2026	Y Intercept Hong Kong Ltd	9,732	$2.24M	0.0%	N/A	0.014%
4/27/2026	Leonteq Securities AG	1,179	$0.27M	0.0%	+66.8%	0.002%
4/27/2026	Fideuram Intesa Sanpaolo Private Banking S.P.A.	2,624	$0.60M	0.0%	N/A	0.004%
4/25/2026	Strs Ohio	45,201	$10.39M	0.0%	-44.1%	0.067%
4/25/2026	Keybank National Association OH	1,308	$0.30M	0.0%	N/A	0.002%
4/24/2026	Root Financial Partners LLC	273	$63K	0.0%	+93.6%	0.000%
4/24/2026	Fulton Bank N.A.	3,228	$0.74M	0.0%	-17.6%	0.005%
4/23/2026	Inspire Investing LLC	9,419	$2.17M	0.2%	-14.0%	0.014%
4/22/2026	Janney Montgomery Scott LLC	8,650	$1.99M	0.0%	-47.5%	0.013%
4/22/2026	Pictet Asset Management Holding SA	10,903	$2.51M	0.0%	+6.4%	0.016%
4/22/2026	Sterling Capital Management LLC	7,058	$1.62M	0.0%	-58.5%	0.010%
4/22/2026	Venturi Wealth Management LLC	2,736	$0.63M	0.0%	-36.6%	0.004%
4/21/2026	GHP Investment Advisors Inc.	50,487	$11.60M	0.5%	+6.2%	0.075%
4/21/2026	Aaron Wealth Advisors LLC	3,928	$0.90M	0.1%	-26.9%	0.006%
4/21/2026	Louisiana State Employees Retirement System	19,500	$4.48M	0.1%	N/A	0.029%
4/21/2026	Fairvoy Private Wealth LLC	3,070	$0.71M	0.2%	N/A	0.005%
4/20/2026	Blue Trust Inc.	4,274	$0.98M	0.0%	+1.1%	0.006%
4/20/2026	Fifth Third Wealth Advisors LLC	2,087	$0.48M	0.0%	+4.1%	0.003%
4/20/2026	OP Asset Management Ltd	2,828	$0.65M	0.0%	N/A	0.004%

Data available starting January 2016

MKS Instruments, Inc. provides foundational technology solutions to semiconductor manufacturing, electronics and packaging, and specialty industrial applications in the United States, Germany, China, South Korea, and internationally. It operates through Vacuum Solutions Division (VSD), Photonics Solutions Division (PSD), and Material Solutions Division (MSD) segments. The VSD segment provides foundational technology solutions, including pressure measurement and control, flow measurement and control, gas and vapor delivery, gas composition analysis, electronic control technology, reactive gas generation and delivery, power generation and delivery, and vacuum technology. The PSD segment offers range of solutions, which include lasers, beam measurement and profiling, precision motion control, vibration isolation systems, photonics instruments, temperature sensing, opto-mechanical components, optical elements, systems for flexible PCB laser processing, and laser-based systems, as well as high density interconnect PCB and package manufacturing. The MSD segment develops, process, and manufactures technologies comprising advanced surface modification, electroless and electrolytic plating, and surface finishing for chemistry, equipment, software, and services markets, as well as high-technology applications. In addition, the company sells its products and services through direct sales, network of independent distributors, and sales representatives, as well as websites, including product catalogs. The company was incorporated in 1961 and is headquartered in Andover, Massachusetts.

Today's Range

Now: $406.37

$382.00

$408.87

50 Day Range

MA: $310.09

$263.25

$406.37

52 Week Range

Now: $406.37

$88.49

$408.87

Volume

2,126,755 shs

Average Volume

1,015,268 shs

Market Capitalization

$27.45 billion

P/E Ratio

85.01

Dividend Yield

0.25%

Beta

1.99

Who are the company insiders with the largest holdings of MKS?: MKS's top insider investors include:
Carlyle Partners Vi Cayman Hol (Major Shareholder)
John Tseng-Chung Lee (CEO)
Leo Berlinghieri (CEO)
Gerard G Colella (Director)
Gerard G Colella (CEO)
Kathleen Flaherty Burke (EVP)
Gerald G Colella (Director)
Seth H Bagshaw (CFO)
Seth H Bagshaw (CFO)
Seth H Bagshaw (VP)
Learn More about top insider investors at MKS.
Who are the major institutional investors of MKS?: MKS's top institutional shareholders include:
Dimensional Fund Advisors LP — 1.24%
Principal Financial Group Inc. — 0.91%
Madison Asset Management LLC — 0.50%
Quantinno Capital Management LP — 0.38%
Systematic Financial Management LP — 0.36%
SummitTX Capital L.P. — 0.24%
Learn More about top institutional investors of MKS stock.
Which major investors are selling MKS stock?: During the last quarter, MKSI stock was sold by these institutional investors:
Royal Bank of Canada
Madison Asset Management LLC
Dimensional Fund Advisors LP
Delta Global Management LP
Principal Financial Group Inc.
Assenagon Asset Management S.A.
SummitTX Capital L.P.
Bessemer Group Inc.
Within the previous year, company insiders that have sold MKS company stock include:
John Tseng-Chung Lee (CEO)
Kathleen Flaherty Burke (EVP)
Gerald G Colella (Director)
David Philip Henry (EVP)
Eric Robert Taranto (EVP)
Elizabeth Mora (Director)
Jacqueline F Moloney (Director)
Joseph B Donahue (Director)
Peter Cannone III (Director)
John Edward Williams (EVP)
Michelle M Mccarthy (CAO)
Ramakumar Mayampurath (CFO)
Learn More investors selling MKS stock.
Which major investors are buying MKS stock?: In the previous quarter, MKSI stock was bought by institutional investors including:
Renaissance Technologies LLC
SG Americas Securities LLC
Bowie Capital Management LLC
SEB Asset Management AB
Segall Bryant & Hamill LLC
Daventry Group LP
Quantinno Capital Management LP
KBC Group NV