Mks MKSI Insider Ownership

NASDAQ MKSI
$268.08 +2.58 (+0.97%)
As of: Sep 9, 2026 · 3:59 PM EDT

Insider Holdings by Owner

13.31Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026
Insider Ownership
0.0078%
0% pp QoQ
Shares Held by Insiders
5.27K
filed for Sep 2026
0.00% QoQ
Shares Outstanding
67.60Mn
67,600,000 shares
Direct Holdings
5.27K
Indirect: 0
Net Shares Traded (QoQ)
0
no net change in Sep 2026
Insiders Holding Shares
21
with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding
Latest
Average ownership
Peak ownership

Shares Purchased/Sold by Insiders

Bought Sold
Latest quarter
Net over range
Buying quarters

Insider Ownership Summary

Quarter ending 30 Sep, 2026

Mks's top three insider shareholders as of September 09, 2026 are Partners Vi Cayman Holdings, L.P. Carlyle (TenPercentOwner, 6.48Mn shares), Partners Vi Cayman Holdings, L.P. Carlyle (TenPercentOwner, 6.48Mn shares), Partners Vi Cayman Holdings, L.P. Carlyle (TenPercentOwner, 6.48Mn shares).

Form 4 Holdings

Insiders Holding MKSI

Insiders 21
Shares held 13.31Mn
Of outstanding 19.69%
# Insider Position Direct Indirect Total Share of Insiders Last Filed
1 Group Inc. Carlyle TenPercentOwner 0 6,482,732 6,482,732 48.7% 10 May, 2023
2 Partners Vi Cayman Holdings, L.P. Carlyle TenPercentOwner 0 6,482,732 6,482,732 48.7% 10 May, 2023
3 John Tseng-Chung Lee President Ceo 134,776 0 134,776 1.0% 17 Aug, 2026
4 Kathleen Flaherty Burke Evp, Gc Secretary 49,439 0 49,439 0.4% 12 May, 2026
5 Gerald G Colella Director 0 20,017 20,017 0.2% 28 May, 2026
6 James Alan Schreiner Evp Coo 19,201 0 19,201 0.1% 16 Jun, 2026
7 Elizabeth Mora Director 18,845 0 18,845 0.1% 02 Sep, 2026
8 Raj Batra Director 16,227 0 16,227 0.1% 12 May, 2026
9 Mark Milton Gitin Evp Gm, Psd 16,134 0 16,134 0.1% 16 Feb, 2024
10 Eric Robert Taranto Evp Gm, Vsd 12,596 0 12,596 0.1% 12 May, 2026
11 Michelle M Warner Director 10,852 0 10,852 0.1% 08 May, 2024
12 David Philip Henry Evp, Global Str Mktg Gm, Msd 10,422 0 10,422 0.1% 02 Jun, 2026
13 Joseph B Donahue Director 10,033 0 10,033 0.1% 28 May, 2026
14 Jacqueline F Moloney Director 8,775 0 8,775 0.1% 15 May, 2026
15 Peter Iii Cannone Director 7,794 0 7,794 0.1% 19 May, 2026
16 Wissam G Jabre Director 5,270 0 5,270 0.0% 12 May, 2026
17 John Edward Williams Evp Gm, Psd 4,098 0 4,098 0.0% 04 Aug, 2026
18 Geoffrey Wild Director 1,813 0 1,813 0.0% 18 Aug, 2022
19 Michelle M Mccarthy Svp Chief Accounting Officer 2 0 2 0.0% 08 Jun, 2026
20 Ramakumar Mayampurath Evp Cfo 1 0 1 0.0% 26 May, 2026
21 Seth H Bagshaw Evp, Cfo Treasurer 1 0 1 0.0% 26 Feb, 2024

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

5,506 Insider Transactions

Source SEC Form 4
Latest quarter Sep 2026
Download Data
Date Insider Position Transaction Shares Price Value Shares Held After Ownership
17 Aug, 2026 Renee Martel Donlan Evp, Gc Cco Acquired A 954 4,781 Direct
03 Aug, 2026 John Edward Williams Evp Gm, Psd Disposed S 457 $288.31 $131.76K 4,098 Direct
10 Jun, 2026 James Alan Schreiner Evp Coo Disposed S 781 $317.42 $247.91K 22,701 Direct
05 Jun, 2026 Michelle M Mccarthy Svp Chief Accounting Officer Disposed S 2,434 $315.23 $767.27K 2 Direct
01 Jun, 2026 David Philip Henry Evp, Global Str Mktg Gm, Msd Disposed S 6,000 $314.43 $1.89Mn 10,422 Direct
27 May, 2026 Joseph B Donahue Director Disposed S 2,100 $327.95 $688.70K 10,033 Direct
27 May, 2026 Gerald G Colella Director Disposed S 464 $330.38 $153.30K 39,553 Indirect
27 May, 2026 Gerald G Colella Director Disposed S 8,210 $331.45 $2.72Mn 31,343 Indirect
27 May, 2026 Gerald G Colella Director Disposed S 4,876 $332.04 $1.62Mn 26,467 Indirect
27 May, 2026 Gerald G Colella Director Disposed S 1,811 $335.46 $607.51K 24,656 Indirect
27 May, 2026 Gerald G Colella Director Disposed S 1,626 $336.54 $547.22K 23,030 Indirect
27 May, 2026 Gerald G Colella Director Disposed S 213 $337.05 $71.79K 22,817 Indirect
27 May, 2026 Gerald G Colella Director Disposed S 2,800 $338.58 $948.02K 20,017 Indirect
26 May, 2026 David Philip Henry Evp, Global Str Mktg Gm, Msd Disposed S 2,500 $330.50 $826.25K 16,341 Direct
22 May, 2026 Ramakumar Mayampurath Evp Cfo Disposed S 8,810 $315.48 $2.78Mn 1 Direct
18 May, 2026 Peter Iii Cannone Director Disposed S 1,350 $303.40 $409.59K 7,794 Direct
14 May, 2026 Jacqueline F Moloney Director Disposed S 1,000 $312.20 $312.20K 8,775 Direct
13 May, 2026 Jacqueline F Moloney Director Disposed S 1,400 $318.99 $446.59K 9,775 Direct
11 May, 2026 Eric Robert Taranto Evp Gm, Vsd Disposed S 2,849 $319.93 $911.33K 12,596 Direct
11 May, 2026 Gerald G Colella Director Acquired A 782 8,999 Direct