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 Mar 31, 2025
Ownership Breakdown
416
Institutional Holders
▼ 20 vs Q4
$5.73B
Total Inst. Value
▼ $1.63B vs Q4
67.54M
Shares Outstanding
freeFloat 99.40%
71.59M
13F Shares Held
▲ 1.08M vs Q4
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
Q1 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
VANGUARD GROUP INC industrial instruments for measurement, display, and control | 7.45M | 11.05% | 11.05% | $597.17B | May 9, 2025 | ▲ 4.7K |
BLACKROCK, INC. industrial instruments for measurement, display, and control | 7.07M | 10.48% | 10.48% | $566.40B | May 2, 2025 | ▼ 53.2K |
FMR LLC industrial instruments for measurement, display, and control | 4.04M | 6.00% | 6.00% | $324.17B | May 12, 2025 | ▼ 176.7K |
PRICE T ROWE ASSOCIATES INC /MD/ industrial instruments for measurement, display, and control | 3.52M | 5.22% | 5.22% | $281.76B | May 14, 2025 | ▲ 173.9K |
VICTORY CAPITAL MANAGEMENT INC industrial instruments for measurement, display, and control | 3.39M | 5.03% | 5.03% | $271.60B | May 2, 2025 | ▲ 300.4K |
WELLINGTON MANAGEMENT GROUP LLP industrial instruments for measurement, display, and control | 3.25M | 4.82% | 4.82% | $260.49B | May 13, 2025 | ▲ 958.6K |
CAPITAL INTERNATIONAL INVESTORS industrial instruments for measurement, display, and control | 3.10M | 4.60% | 4.60% | $248.38B | May 12, 2025 | ▲ 1.3K |
NORDEA INVESTMENT MANAGEMENT AB industrial instruments for measurement, display, and control | 2.27M | 3.37% | 3.37% | $178.61B | May 14, 2025 | ▼ 251.8K |
STATE STREET CORP industrial instruments for measurement, display, and control | 2.08M | 3.09% | 3.09% | $166.93B | May 15, 2025 | ▲ 13.1K |
INVESCO LTD. industrial instruments for measurement, display, and control | 2.05M | 3.04% | 3.04% | $164.27B | May 12, 2025 | ▼ 181.9K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q1 2025 vs prior quarter
Q1 2025
31
Increased
+4.71M shares1
New Positions
first time holders15
Decreased
−1.02M shares0
Sold Out
fully exitedNet shares change (top 50)
+3.69M
+4.71M / −1.02M
Net new holders
+17
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 7.45 million shares — equal to 11.05% of outstanding shares — as of March 31, 2025.
A total of 416 institutional investors currently hold MKSI stock, with a combined institutional value of approximately $5.73 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 11.05% stake. Company insiders hold 0.60%. Data sourced from SEC Form 13F as of March 31, 2025.