MKS Ownership & Insider Activity

MKS (MKSI) institutional and insider ownership, recent insider transactions and ownership breakdown.

Insiders own 1.2% of shares outstanding. Institutional investors hold 67.3%. Over the past 90 days, insiders made 3 sales worth $3.2M.

Shares Outstanding

67.248M

Shares Float

53.096M

Insider Shares Owned

784.617K

Insider % Owned

1.2%

Institutional Shares Held

45.487M

Institutional % Held

67.3%

Ownership Breakdown

Net Insider Activity by Month

Purchases (90d)

Sales (90d)

$3.2M total

Net Activity

Net Selling

Net Value (90d)

-$3.2M

MKS Insider Transactions (Last 6 Months)

Date	Insider	Title	Type	Shares	Price	Value
Sep 1, 2026	Elizabeth Mora	DIRECTOR	SELL	300.000	$250.96	$75K
Aug 14, 2026	TsengChung John Lee	PRESIDENT & CEO	SELL	10.000K	$302.01	$3.0M
Aug 3, 2026	Edward John Williams	EVP & GM, PSD	SELL	457.000	$288.31	$132K
Jun 12, 2026	Alan James Schreiner	EVP & COO	SELL	3.500K	$345.82	$1.2M
Jun 10, 2026	Alan James Schreiner	EVP & COO	SELL	781.000	$317.42	$248K
Jun 5, 2026	Michelle McCarthy	SVP & CHIEF ACCOUNTING OFFICER	SELL	2.434K	$315.23	$767K
Jun 1, 2026	Philip David Henry	EVP, GLOBAL STR MKTG & GM, MSD	SELL	6.000K	$314.43	$1.9M
Jun 1, 2026	Elizabeth Mora	DIRECTOR	SELL	300.000	$318.02	$95K
May 27, 2026	Joseph Donahue	DIRECTOR	SELL	2.100K	$327.95	$689K
May 27, 2026	GERALD COLELLA	DIRECTOR	SELL	20.000K	$333.40	$6.7M
May 26, 2026	Philip David Henry	EVP, GLOBAL STR MKTG & GM, MSD	SELL	2.500K	$330.50	$826K
May 22, 2026	Ramakumar Mayampurath	EVP & CFO	SELL	8.810K	$315.48	$2.8M
May 22, 2026	TsengChung John Lee	PRESIDENT & CEO	SELL	10.000K	$315.48	$3.2M
May 18, 2026	PETER CANNONE III	DIRECTOR	SELL	1.350K	$303.40	$410K
May 14, 2026	Jacqueline Moloney	DIRECTOR	SELL	1.000K	$312.20	$312K
May 13, 2026	Jacqueline Moloney	DIRECTOR	SELL	1.400K	$318.99	$447K
May 11, 2026	Robert Eric Taranto	EVP & GM, VSD	SELL	2.849K	$319.93	$911K
May 11, 2026	Flaherty Kathleen Burke	EVP, GC & SECRETARY	SELL	4.355K	$319.94	$1.4M

Date	Member	Party	Chamber	Action	Amount
Oct 31, 2025	Lisa McClain	R	House	Sale	$1,001 - $15,000
Oct 30, 2025	Lisa McClain	R	House	Sale	$1,001 - $15,000
Oct 30, 2025	Lisa McClain	R	House	Purchase	$1,001 - $15,000
Aug 4, 2025	Lisa McClain	R	House	Purchase	$1,001 - $15,000