Does Citadel Advisors own MKSI stock?

Yes. As of its Q2 2026 13F, Citadel Advisors holds 697,670 shares of MKSI (MKS), worth $310.3M.

How many shares of MKSI does Citadel Advisors own?

As of its Q2 2026 13F, Citadel Advisors holds 697,670 shares of MKSI (MKS).

As of its Q2 2026 13F, Citadel Advisors' MKSI position is worth $310.3M.

In Q2 2026, Citadel Advisors reduced its MKSI position by 249,362 shares (-26.3%).

Citadel Advisors already held MKSI in its Q4 2018 13F, the earliest on record, and has listed it in 27 quarterly 13F filings.

Position history for CITADEL ADVISORS LLC's holdings in MKS INC

Current Value

$310.3M

Current Shares

697,670

Total Value Change

+$307M

Total Shares Change

+645,601

Quarter-by-Quarter History

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2026-Q2 Latest	Decreased	697,670	-26.3%	$310.3M	0.0%	$444.39	0
2026-Q1	Increased	947,032	+106.8%	$217.6M	0.0%	$229.42	49
2025-Q4	Increased	457,873	+224.4%	$73.2M	0.0%	$159.38	48
2025-Q3	Decreased	141,158	-3.3%	$17.5M	0.0%	$123.25	0
2025-Q2	New	146,038	-	$14.5M	0.0%	$98.74	39
2025-Q1	Exited	0	-100.0%	$0	0.0%	$79.44	0
2024-Q4	Decreased	37,120	-63.5%	$3.9M	0.0%	$103.24	0
2024-Q3	Increased	101,583	+110.3%	$11M	0.0%	$107.31	45
2024-Q2	New	48,308	-	$6.3M	0.0%	$128.67	38
2024-Q1	Exited	0	-100.0%	$0	0.0%	$130.83	0
2023-Q4	Increased	27,638	+417.7%	$2.8M	0.0%	$101.01	42
2023-Q3	Decreased	5,339	-94.6%	$462,037	0.0%	$84.73	0
2023-Q2	Increased	99,128	+85.0%	$10.7M	0.0%	$105.60	43
2023-Q1	Increased	53,593	+3917.5%	$4.7M	0.0%	$86.36	43
2022-Q4	Decreased	1,334	-80.0%	$113,030	0.0%	$82.38	0
2022-Q3	Decreased	6,678	-96.2%	$552,000	0.0%	$80.13	0
2022-Q2	New	174,377	-	$17.9M	0.0%	$99.33	39
2022-Q1	Exited	0	-100.0%	$0	0.0%	$144.91	0
2021-Q4	Decreased	20,233	-47.1%	$3.5M	0.0%	$168.01	0
2021-Q3	Decreased	38,254	-34.3%	$5.8M	0.0%	$145.37	0
2021-Q2	Increased	58,203	+310.7%	$10.4M	0.0%	$171.16	45
2021-Q1	Decreased	14,173	-92.0%	$2.6M	0.0%	$178.13	0
2020-Q4	Increased	178,150	+67.2%	$26.8M	0.0%	$144.36	42
2020-Q3	Increased	106,561	+21.1%	$11.6M	0.0%	$104.65	33
2020-Q2	Increased	88,003	+80.7%	$10M	0.0%	$108.31	42
2020-Q1	Increased	48,701	+371.9%	$4M	0.0%	$77.75	43
2019-Q4	New	10,319	-	$1.1M	0.0%	$104.84	35
2019-Q3	Exited	0	-100.0%	$0	0.0%	$87.77	0
2019-Q2	Increased	153,876	+2279.8%	$12M	0.0%	$73.89	45
2019-Q1	Decreased	6,466	-87.6%	$602,000	0.0%	$88.04	0
2018-Q4	First report	52,069	-	$3.4M	0.0%	$60.99	0