MKS INSTRS INC

Ticker: MKSI CUSIP: 55306N104 Class: EQTY

Weiss Asset Management LP's Holding History (CIK: 0001357550)

Note: Option positions (PUT/CALL) are excluded.

Q3 2025

Shares 111,075 Value ($000) $13,748 Avg Close $106.31 Range $88.17 - $132.24

Q3 2024

Shares 17,009 Value ($000) $1,849 Avg Close $117.45 Range $99.10 - $145.63

Q4 2023

Shares 18,561 Value ($000) $1,909 Avg Close $79.84 Range $62.28 - $104.49

Q1 2022

Shares 1,399 Value ($000) $210 Avg Close $150.35 Range $131.30 - $175.09

Period	Shares	Value ($000)	Average Close	Price Range
Q3 2025	111,075	$13,748	$106.31	$88.17 - $132.24
Q3 2024	17,009	$1,849	$117.45	$99.10 - $145.63
Q4 2023	18,561	$1,909	$79.84	$62.28 - $104.49
Q1 2022	1,399	$210	$150.35	$131.30 - $175.09