MKS (MKSI) Institutional Ownership & Top Holders
The most recent SEC Form 13F filings (Q1 2026) show 12 hedge funds and institutional investors holding a combined 4.3M shares of MKS (MKSI), valued at $999.3M. The median portfolio weight is 4.4%.
The latest institutional ownership changes for MKSI show net buying, with the combined position up by 3.8M shares (747.8%) from the previous quarter.
Among 13F filers, the funds with the highest portfolio allocation to MKSI are FengHe Fund Management (14.5% of its 13F portfolio), Blue Grotto Capital (9.9%), and LIGHT STREET CAPITAL MANAGEMENT (5.6%). In Q1 2026, FengHe Fund Management made the largest position increase (+14.5%), while UTIMCO - The University of Texas made the largest reduction (-0.0%).
Top 10 Institutional Holders in MKS (MKSI), Ranked by Portfolio Weight
Based on the latest SEC Form 13F filings (Q1 2026).
| # | Fund | Shares | Market Value | Portfolio Weight |
|---|---|---|---|---|
| 1 | FengHe Fund Management | 456,329 | $104.9M | 14.5% |
| 2 | Blue Grotto Capital | 375,000 | $86.2M | 9.9% |
| 3 | LIGHT STREET CAPITAL MANAGEMENT | 122,264 | $28.1M | 5.6% |
| 4 | Aspex | 1,538,789 | $353.6M | 5.1% |
| 5 | Divisar Capital Management | 85,501 | $19.6M | 5.0% |
| 6 | Talos Eurisko Asset Management | 114,011 | $26.2M | 4.5% |
| 7 | Rivermont Capital Management | 87,537 | $20.1M | 4.2% |
| 8 | Whale Rock | 1,306,724 | $300.3M | 3.9% |
| 9 | Dendur Capital | 214,500 | $49.3M | 3.6% |
| 10 | Tyro Capital Management | 36,855 | $8.5M | 2.1% |
- 12Institutional investors
- 4,348,266Shares held (disclosed)
- $999.3M13F market value
- 4.4%Median portfolio weight
Ownership History
Quarter-by-quarter share count, market value, and portfolio conviction weight (up to 5 of the heaviest weight-by-portfolio funds) of MKSI. Sourced from 13F filings; reflects long equity positions only.
Quarter-over-Quarter ActivityQ1 2026
The biggest weight-increase and weight-decrease changes among funds that hold MKSI. Deltas compare the selected filing to the previous reporting quarter.
Top buyers
- FengHe Fund Management+14.5% · +456,329 shares
- LIGHT STREET CAPITAL MANAGEMENT+5.2% · +102,682 shares
- Aspex+5.1% · +1,538,789 shares
Top sellers
- UTIMCO - The University of Texas-0.0% · -275 shares
- Blue Grotto Capital3.1% · -40,500 shares
Ownership Statistics
- Funds holding
- 12
- Median weight
- 4.4%
- Largest holder
- FengHe Fund Management · 14.5%
- Smallest holder
- Maverick Capital · 0.0%
- Shares held
- 4,348,266 (+3,835,408)
All Institutional HoldersSortable · searchable
All institutional investors (Max 50) holding MKSI in the selected quarter. Click a fund name to drill into its full 13F portfolio.
| 1 | FengHe Fund Management | 456,329 | $104.9M | 14.5% |
| 2 | Blue Grotto Capital | 375,000 | $86.2M | 9.9% |
| 3 | LIGHT STREET CAPITAL MANAGEMENT | 122,264 | $28.1M | 5.6% |
| 4 | Aspex | 1,538,789 | $353.6M | 5.1% |
| 5 | Divisar Capital Management | 85,501 | $19.6M | 5.0% |
| 6 | Talos Eurisko Asset Management | 114,011 | $26.2M | 4.5% |
| 7 | Rivermont Capital Management | 87,537 | $20.1M | 4.2% |
| 8 | Whale Rock | 1,306,724 | $300.3M | 3.9% |
| 9 | Dendur Capital | 214,500 | $49.3M | 3.6% |
| 10 | Tyro Capital Management | 36,855 | $8.5M | 2.1% |
| 11 | Monolith | 3,470 | $797.4K | 0.3% |
| 12 | Maverick Capital | 7,286 | $1.7M | 0.0% |
Institutional Investor Count Over Time
Number of institutional investors disclosing a long position in MKS INC. (MKSI) each reporting quarter. Sourced from SEC Form 13F-HR filings.
Methodology & FAQ
Methodology: How We Track MKSI Institutional Holdings
Our data is systematically aggregated directly from quarterly Form 13F-HR disclosures submitted to the U.S. Securities and Exchange Commission (SEC).
- Who Must File (Reporting Threshold): This dataset includes filings from U.S. institutional investment managers, hedge funds, mutual funds, university endowments, and family offices managing at least $100 million in Section 13(f) securities (including equities, options, convertibles, ETFs, and warrants).
- What is Included (Data Scope): We capture long positions in Section 13(f) securities for MKS INC. (MKSI). By SEC regulation, 13F filings do not require the disclosure of short positions, non-U.S. holdings, or OTC derivatives. Listed options are excluded from portfolio weight calculations to ensure comparability across filers.
- Portfolio Weight Explained (Metric Definition): “Portfolio Weight” shows how much of a fund's total reported 13F portfolio value (excluding listed options) is allocated to MKSI on the specific reporting date.
- How to Use This Data (Interpretation): Quarter-over-quarter changes in shares and portfolio weight reflect a combination of active trading and market price movements. These are descriptive metrics of fund allocation, not explicit buy or sell signals.
How do you measure hedge fund conviction and institutional concentration in MKSI?
We evaluate fund conviction by looking at portfolio weight rather than just absolute share count. By tracking how the largest holders —such as FengHe Fund Management , Blue Grotto Capital , and LIGHT STREET CAPITAL MANAGEMENT as of Q1 2026— change their position sizing quarter-over-quarter, we help investors distinguish between deliberate position sizing changes and passive mark-to-market drift.
Does the MKSI ownership data include short interest or options?
SEC Form 13F mandates the disclosure of long positions in Section 13(f) securities, which includes equities and listed options (put and call contracts), but excludes short interest, swaps, and OTC derivatives by regulatory design. On this platform, listed options are excluded from portfolio weight calculations to ensure comparability across filers.
Are family offices and university endowments included in this MKSI data?
Yes. In addition to traditional hedge funds and large asset managers, any institutional entity exercising investment discretion over at least $100 million in Section 13(f) securities must file a Form 13F. This explicitly includes single-family offices and university endowments. If a qualifying family office or endowment holds MKSI stock, their allocation is systematically aggregated alongside traditional fund data.
When is the institutional ownership data updated, and is there a reporting lag?
Institutional investment managers are required to file their Form 13F within 45 days after the end of a calendar quarter (the standard “T+45” window). Our platform re-ingests new filings from the SEC EDGAR database on a nightly cycle, typically within 24–48 hours of publication, providing a point-in-time snapshot of reported consensus positioning for MKSI as of each filing date.