MKS Inc.
MKS Inc. (MKSI) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · MKSI · as of Sep 30, 2025
Ownership Breakdown
456
Institutional Holders
▲ 41 vs Q2
$8.91B
Total Inst. Value
▲ $1.49B vs Q2
67.54M
Shares Outstanding
freeFloat 99.40%
72.01M
13F Shares Held
▼ 2.67M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
MKSI largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
VANGUARD GROUP INC industrial instruments for measurement, display, and control | 7.75M | 11.54% | 11.54% | $959.48B | Nov 7, 2025 | ▲ 295.5K |
BLACKROCK, INC. industrial instruments for measurement, display, and control | 6.12M | 9.11% | 9.11% | $757.88B | Nov 12, 2025 | ▼ 1.19M |
PRICE T ROWE ASSOCIATES INC /MD/ industrial instruments for measurement, display, and control | 3.63M | 5.41% | 5.41% | $449.66B | Nov 14, 2025 | ▼ 496.1K |
VICTORY CAPITAL MANAGEMENT INC industrial instruments for measurement, display, and control | 3.58M | 5.33% | 5.33% | $443.37B | Nov 12, 2025 | ▼ 284.0K |
FMR LLC industrial instruments for measurement, display, and control | 3.44M | 5.12% | 5.12% | $426.17B | Nov 13, 2025 | ▼ 386.1K |
CAPITAL INTERNATIONAL INVESTORS industrial instruments for measurement, display, and control | 3.25M | 4.84% | 4.84% | $402.83B | Nov 13, 2025 | ▲ 2.1K |
WELLINGTON MANAGEMENT GROUP LLP industrial instruments for measurement, display, and control | 3.01M | 4.48% | 4.48% | $373.02B | Nov 14, 2025 | ▲ 14.3K |
INVESCO LTD. industrial instruments for measurement, display, and control | 2.38M | 3.55% | 3.55% | $294.99B | Nov 13, 2025 | ▲ 446.8K |
STATE STREET CORP industrial instruments for measurement, display, and control | 2.04M | 3.04% | 3.04% | $252.98B | Nov 14, 2025 | ▼ 13.7K |
NEUBERGER BERMAN GROUP LLC industrial instruments for measurement, display, and control | 1.63M | 2.43% | 2.43% | $202.34B | Nov 12, 2025 | ▼ 253.8K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
25
Increased
+5.60M shares1
New Positions
first time holders21
Decreased
−5.91M shares0
Sold Out
fully exitedNet shares change (top 50)
311.9K
+5.60M / −5.91M
Net new holders
+5
1 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
MKSI insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
12
Buy transactions
24
Sell transactions
0.50
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Henry David Philip EVP, Global Str Mktg & GM, MSD | Jun 1, 2026 | Sale | 6,000 | $314.43 | $1.89M | 10.4K | Form 4 ↗ |
Mora Elizabeth director | Jun 1, 2026 | Sale | 300 | $318.02 | $95.4K | 19.1K | Form 4 ↗ |
Donahue Joseph B director | May 27, 2026 | Sale | 2,100 | $327.95 | $688.7K | 10.0K | Form 4 ↗ |
COLELLA GERALD G director | May 27, 2026 | Sale | 464 | $330.38 | $153.3K | 39.6K | Form 4 ↗ |
COLELLA GERALD G director | May 27, 2026 | Sale | 8,210 | $331.45 | $2.72M | 31.3K | Form 4 ↗ |
COLELLA GERALD G director | May 27, 2026 | Sale | 4,876 | $332.04 | $1.62M | 26.5K | Form 4 ↗ |
COLELLA GERALD G director | May 27, 2026 | Sale | 1,811 | $335.46 | $607.5K | 24.7K | Form 4 ↗ |
COLELLA GERALD G director | May 27, 2026 | Sale | 1,626 | $336.54 | $547.2K | 23.0K | Form 4 ↗ |
COLELLA GERALD G director | May 27, 2026 | Sale | 213 | $337.05 | $71.8K | 22.8K | Form 4 ↗ |
COLELLA GERALD G director | May 27, 2026 | Sale | 2,800 | $338.58 | $948.0K | 20.0K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
MKS Inc. (MKSI) is primarily owned by institutional investors, who hold approximately 100.0% of total shares outstanding. Company insiders own approximately 0.60%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of MKS Inc. is VANGUARD GROUP INC, holding approximately 7.75 million shares — equal to 11.54% of outstanding shares — as of September 30, 2025.
A total of 456 institutional investors currently hold MKSI stock, with a combined institutional value of approximately $8.91 billion as of the most recent 13F filing period.
Frequently asked questions
MKSI ownershipMKS Inc. (MKSI) is primarily owned by institutional investors, who hold approximately 100.0% of shares. The largest shareholder is VANGUARD GROUP INC with a 11.54% stake. Company insiders hold 0.60%. Data sourced from SEC Form 13F as of September 30, 2025.