William Blair & Company’s MKS Inc MKSI Stock Holding History

William Blair & Company’s Portfolio MKSI Stock Details MKSI Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q2	$285K	Buy	+641	New	+$201K	﹤0.01%	1440
2023 Q3	–	Sell	-3,830	Closed	-$414K	–	1822
2023 Q2	$414K	Buy	3,830 +590	+18%	+$54K	﹤0.01%	1115
2023 Q1	$287K	Buy	3,240 +19	+0.6%	+$1.81K	﹤0.01%	1259
2022 Q4	$273K	Sell	3,221 -183	-5%	-$14.7K	﹤0.01%	1266
2022 Q3	$281K	Sell	3,404 -292	-8%	-$30.1K	﹤0.01%	1255
2022 Q2	$379K	Sell	3,696 -119	-3%	-$13.9K	﹤0.01%	1173
2022 Q1	$572K	Buy	3,815 +1,345	+54%	+$209K	﹤0.01%	1109
2021 Q4	$430K	Buy	+2,470	New	+$386K	﹤0.01%	1275

Other funds holding MKSI

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Invesco Atlanta, Georgia $1.26T AUM 61.52% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

JP Morgan Chase New York $1.81T AUM 41.13% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Point72 Asset Management Stamford, Connecticut $90.7B AUM 77.13% 1-Year Est. Return

Capital International Investors Los Angeles, California $484B AUM 34.9% 1-Year Est. Return

T. Rowe Price Associates Baltimore, Maryland $999B AUM 46.22% 1-Year Est. Return

AMH

Aspex Management (HK) Central, Hong Kong $8.89B AUM 39.91% 1-Year Est. Return

William Blair & Company's MKSI Position: Q2 2026 in Review

William Blair & Company opened a new position in MKS Inc (MKSI) in Q2 2026: 641 shares worth $285K. The stake represents ﹤0.01% of the portfolio and ranks #1440 among its holdings. This is a return to the name: William Blair & Company previously reported a position in MKSI as recently as Q2 2023.

William Blair & Company first reported a position in MKSI in Q4 2021 and has held it in 8 quarters since. The position peaked at $572K in Q1 2022. 775 funds tracked by Wall St. Rank hold MKSI as of Q2 2026.

William Blair & Company held 641 shares of MKS Inc worth $285K as of Q2 2026.
MKS Inc was a new William Blair & Company position in Q2 2026.
MKS Inc made up ﹤0.01% of William Blair & Company's portfolio in Q2 2026, its #1440 holding.
William Blair & Company first reported a position in MKS Inc in Q4 2021 and has held it in 8 quarters since.
William Blair & Company's MKS Inc position peaked at $572K in Q1 2022.
775 funds tracked by Wall St. Rank held MKS Inc as of Q2 2026.

Based on William Blair & Company's 13F filing for Q2 2026, filed 11 Aug 2026.