MKS Inc. (MKSI)
Nasdaq: MKSI · Industrial Instruments For Measurement, Display, and Control · Andover, MA · filing with the SEC since 1997
Grade5.4
◀ Past 5.8● Present 5.2▶ Future 5.1
Who owns MKS Inc.
As filed with the SECHolders of 5% or more
4
Blackrock, Inc. holds 8.8% of Common Stock, as its SCHEDULE 13G/A filed Oct 17, 2025 says.
Directors and officers
16
report now, of 31 people on the record since 2006. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 4 named at left.
Holders of 5% or moreshare of the class, as filed
Blackrock, Inc.
SCHEDULE 13G/A · filed Oct 17, 2025 · Common Stock
Invesco LTD
SCHEDULE 13G · filed Feb 12, 2026 · Common Stock
Vanguard Portfolio Management
SCHEDULE 13G · filed Apr 29, 2026 · Common Stock
Vanguard Capital Management
SCHEDULE 13G · filed Apr 30, 2026 · Common Stock
Capital International Investors
SCHEDULE 13G/A · filed Feb 7, 2025 · Common Stock · reported falling below 5%
T. Rowe Price Associates, Inc.
SCHEDULE 13G/A · filed Feb 17, 2026 · COMMON STOCK · reported falling below 5%, from 6.2% in Aug 14, 2025
Fmr LLC
SCHEDULE 13G/A · filed May 6, 2026 · COMMON STOCK · reported falling below 5%
JPMorgan Chase & Co.
SCHEDULE 13G/A · filed Sep 3, 2026 · Common Stock, no par value · reported falling below 5%, from 5% in Jul 16, 2026
Victory Capital Management, Inc.
SCHEDULE 13G/A · filed Jul 24, 2026 · Common Stock · reported falling below 5%, from 5.64% in Aug 8, 2025
The Vanguard Group
SCHEDULE 13G/A · filed Mar 27, 2026 · Common Stock · reported falling below 5%, from 11.5% in Oct 31, 2025
What MKSI reports owning in othersstakes of 5% or more, and other ties
95 subsidiaries in 37 countries, from the list filed with the 10-K filed Feb 24, 2026.
Insider tradesForm 4
45sales
0purchases
18sales on a scheduled plan
13people selling
$43.4Msold, in dollars
$0bought, in dollars
Open-market trades on Form 4 from Nov 3, 2025 to Nov 3, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
2026 runs to Nov 3, 2026. Dollars as filed, summed by the transaction date.
People who traded in the window13 of 47 on the roster
| Person | Role as filed | Sales | Sold | On a plan | Buys | Bought |
|---|---|---|---|---|---|---|
| Lee John Tseng-Chung | President & CEO | 6 | $13.9M | 2 | 0 | $0 |
| Colella Gerard G | CEO, Director | 9 | $11.7M | 7 | 0 | $0 |
| Henry David Philip | EVP, Global Str Mktg & GM, MSD | 3 | $3.2M | 1 | 0 | $0 |
| Mayampurath Ramakumar | EVP & CFO | 1 | $2.8M | 1 | 0 | $0 |
| Schreiner James Alan | EVP & COO | 5 | $2.5M | 1 | 0 | $0 |
| Burke Kathleen Flaherty | EVP, GC & Secretary | 2 | $2.5M | 0 | 0 | $0 |
| Taranto Eric Robert | EVP & GM, VSD | 3 | $2.3M | 0 | 0 | $0 |
| Mccarthy Michelle M | SVP & Chief Accounting Officer | 3 | $1.1M | 1 | 0 | $0 |
| Moloney Jacqueline F | director | 4 | $1.0M | 0 | 0 | $0 |
| Williams John Edward | EVP & GM, PSD | 2 | $700,000 | 1 | 0 | $0 |
| Donahue Joseph B | director | 1 | $700,000 | 0 | 0 | $0 |
| Cannone Peter III | director | 2 | $700,000 | 0 | 0 | $0 |
| Mora Elizabeth | director | 4 | $300,000 | 4 | 0 | $0 |