Company · Ownership research

MKS INC MKSI

CIK 0001049502 · CUSIP 55306N104

Insider trading Initial holdings Institutional holders

Quarter-end disclosures, not live holdings.

Several CUSIPs are reported for this company; this page shows CUSIP 55306N104 (MKSI), not CUSIP 55306N904 (MKSI), CUSIP 55306N954 (MKSI), and does not merge CUSIPs.

This page lists the top 20 of 401 rows by value; the complete set is available through the API.

Some filings reported values in thousands; those figures were scaled ×1,000 to dollars.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value

#	Manager	Value	Manager weight	Change vs prior	Source
01	VANGUARD GROUP INC CIK 102909 · View history	$597.17M 7,450,615 shares	0.01%	+4.66K(+0.10%)Added	SEC filing ↗ May 9, 2025	▾
02	BlackRock, Inc. CIK 2012383 · View history	$566.40M 7,066,707 shares	0.01%	-53.18K(-0.70%)Reduced	SEC filing ↗ May 2, 2025	▾
03	FMR LLC CIK 315066 · Amended · View history	$324.17M 4,044,555 shares	0.02%	-176.72K(-4.20%)Reduced	SEC filing ↗ Nov 5, 2026	▾
04	PRICE T ROWE ASSOCIATES INC /MD/ CIK 80255 · View history	$281.76M 3,515,373 shares	0.03%	+173.94K(+5.20%)Added	SEC filing ↗ May 14, 2025	▾
05	VICTORY CAPITAL MANAGEMENT INC CIK 1040188 · View history	$271.60M 3,388,639 shares	0.28%	+300.36K(+9.70%)Added	SEC filing ↗ May 2, 2025	▾
06	WELLINGTON MANAGEMENT GROUP LLP CIK 902219 · View history	$260.49M 3,250,085 shares	0.05%	+958.61K(+41.80%)Added	SEC filing ↗ May 13, 2025	▾
07	Capital International Investors CIK 1562230 · View history	$248.38M 3,098,999 shares	0.05%	+1.32K(0.00%)Added	SEC filing ↗ May 12, 2025	▾
08	NORDEA INVESTMENT MANAGEMENT AB CIK 1218210 · View history	$178.61M 2,273,283 shares	0.19%	-251.75K(-10.00%)Reduced	SEC filing ↗ May 14, 2025	▾
09	STATE STREET CORP CIK 93751 · View history	$166.93M 2,082,712 shares	0.01%	+13.13K(+0.60%)Added	SEC filing ↗ May 15, 2025	▾
10	Invesco Ltd. CIK 914208 · View history	$164.27M 2,049,563 shares	0.03%	-181.90K(-8.20%)Reduced	SEC filing ↗ May 12, 2025	▾
11	NEUBERGER BERMAN GROUP LLC CIK 1465109 · Amended · View history	$155.81M 1,943,939 shares	0.13%	+159.81K(+9.00%)Added	SEC filing ↗ Oct 27, 2026	▾
12	Madison Asset Management, LLC CIK 1299351 · View history	$114.47M 1,428,143 shares	1.28%	+494.21K(+52.90%)Added	SEC filing ↗ May 6, 2025	▾
13	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$98.06M 1,223,043 shares	0.01%	+48.82K(+4.20%)Added	SEC filing ↗ May 13, 2025	▾
14	COOKE & BIELER LP CIK 24386 · View history	$83.27M 1,038,945 shares	0.83%	+161.91K(+18.50%)Added	SEC filing ↗ May 2, 2025	▾
15	NORGES BANK CIK 1374170 · Amended · View history	$72.50M 904,502 shares	0.01%	+85.93K(+10.50%)Added	SEC filing ↗ May 13, 2025	▾
16	DIMENSIONAL FUND ADVISORS LP CIK 354204 · View history	$70.42M 878,681 shares	0.02%	+252.54K(+40.30%)Added	SEC filing ↗ May 13, 2025	▾
17	PRINCIPAL FINANCIAL GROUP INC CIK 1126328 · View history	$66.94M 835,195 shares	0.04%	-1.19K(-0.10%)Reduced	SEC filing ↗ Apr 28, 2025	▾
18	UBS Group AG CIK 1610520 · View history	$64.75M 807,853 shares	0.01%	+134.89K(+20.00%)Added	SEC filing ↗ May 13, 2025	▾
19	ROYCE & ASSOCIATES LP CIK 906304 · View history	$63.58M 793,244 shares	0.69%	+53.80K(+7.30%)Added	SEC filing ↗ May 6, 2025	▾
20	CHARLES SCHWAB INVESTMENT MANAGEMENT INC CIK 884546 · Amended · View history	$57.57M 718,239 shares	0.01%	+51.84K(+7.80%)Added	SEC filing ↗ Sep 15, 2025	▾

Showing 20 / 401 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

401

Cancelled or null records excluded

Disclosed shares

71,560,411

Not deduplicated across managers

Disclosed value

$5.73B

Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

MKS INC · Q1 2025

Explore all 401 reporting institutions.

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Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.