Ticker · CUSIP 55306N104
Holders (tracked)
15
Combined shares
8,653,600
Combined value
$943.22M
Last close
—
Quarter
2025Q4
Tracked holders · last 8 quarters
+4 vs previous quarter over the last 8.
SEC event timeline
23 events
- Ken Griffin (Citadel Advisors) added2026-02-17+316,715 shares · 2025Q4Position
- Two Sigma Investments added2026-02-17+23,158 shares · 2025Q4Position
- Izzy Englander (Millennium Mgmt) added2026-02-17+371,003 shares · 2025Q4Position
- Steve Cohen (Point72) trimmed2026-02-17−387,754 shares · 2025Q4Position
- T. Rowe Price trimmed2026-02-17−879,169 shares · 2025Q4Position
- Wellington Management trimmed2026-02-17−461,774 shares · 2025Q4Position
- +104,482 shares · 2025Q4Position
- +19,582 shares · 2025Q4Position
- Larry Robbins (Glenview Capital) trimmed2026-02-17−97,722 shares · 2025Q4Position
- AQR Capital Management added2026-02-17+26,665 shares · 2025Q4Position
- Norges Bank (Norway SWF) opened position2026-02-10+922,737 shares · 2025Q4Position
- Mario Gabelli (GAMCO) trimmed2026-02-05−4,000 shares · 2025Q4Position
- Izzy Englander (Millennium Mgmt) added2025-11-14+441,432 shares · 2025Q3Position
- Steve Cohen (Point72) opened position2025-11-14+1,013,553 shares · 2025Q3Position
- Two Sigma Investments added2025-11-14+1,400 shares · 2025Q3Position
- Wellington Management added2025-11-14+14,341 shares · 2025Q3Position
- Larry Robbins (Glenview Capital) trimmed2025-11-14−60,374 shares · 2025Q3Position
- T. Rowe Price trimmed2025-11-14−496,109 shares · 2025Q3Position
- D.E. Shaw & Co. exited2025-11-14−96,288 shares · 2025Q3Position
- AQR Capital Management trimmed2025-11-14−15,050 shares · 2025Q3Position
- Norges Bank (Norway SWF) exited2025-11-13−859,406 shares · 2025Q3Position
- Norges Bank (Norway SWF) added2025-11-12+40,336 shares · 2024Q3Position
- Mario Gabelli (GAMCO) trimmed2025-11-12−600 shares · 2025Q3Position
Insider activity
Last 30 days
Net (open-market)
$0
Buys
0 · $0
Sells
0 · $0
Unique insiders
1
| Date | Insider | Code | Shares | Price | Value |
|---|---|---|---|---|---|
| 04-15 | McCarthy Michelle M SVP & Chief Accounting Officer · Officer | M | 968 | — | — |
| 04-15 | McCarthy Michelle M SVP & Chief Accounting Officer · Officer | M | 1,107 | — | — |
| 04-15 | McCarthy Michelle M SVP & Chief Accounting Officer · Officer | M | 1,736 | — | — |
| 04-15 | McCarthy Michelle M SVP & Chief Accounting Officer · Officer | F | 1,375 | $274.15 | $377.1K |
Who moved on this name in 2025Q4
Position changes reported for the latest quarter, grouped by direction.
New positions3
- Norges Bank (Norway SWF)+922,737$147.5M
- Paul Tudor Jones (Tudor Investment)+104,482$16.7M
- Glen Kacher (Light Street Capital)+19,582$3.1M
Added to4
- Izzy Englander (Millennium Mgmt)+371,003$59.3M
- Ken Griffin (Citadel Advisors)+316,715$50.6M
- AQR Capital Management+26,665$4.3M
- Two Sigma Investments+23,158$3.7M
Trimmed5
- Wellington Management−461,774$73.8M
- Steve Cohen (Point72)−387,754$62.0M
- Larry Robbins (Glenview Capital)−97,722$15.6M
- Mario Gabelli (GAMCO)−4,000$639K
- T. Rowe Price−879,169$140K
Exited0
—
Institutional ownership over time
Distinct super-investors holding this ticker · combined dollar value, by quarter.
| Quarter | Holders | Combined value |
|---|---|---|
| 2022Q1 | 12 | $87.36B |
| 2022Q2 | 15 | $69.05B |
| 2022Q3 | 15 | $66.4M |
| 2022Q4 | 14 | $731.1M |
| 2023Q1 | 14 | $787.8M |
| 2023Q2 | 13 | $1.16B |
| 2023Q3 | 13 | $719.2M |
| 2023Q4 | 11 | $838.6M |
| 2024Q1 | 11 | $1.55B |
| 2024Q2 | 15 | $1.58B |
| 2024Q3 | 14 | $497.2M |
| 2024Q4 | 14 | $271.8M |
| 2025Q1 | 13 | $395.4M |
| 2025Q2 | 14 | $459.1M |
| 2025Q3 | 11 | $626.0M |
| 2025Q4 | 15 | $943.2M |
Congress members trading this stock
| Date | Member | Type | Amount range | Filing |
|---|---|---|---|---|
| 2025-10-31 | Lisa McClain | Sell | $1K – $15K | PDF ↗ |
| 2025-10-30 | Lisa McClain | Buy | $1K – $15K | PDF ↗ |
| 2025-10-30 | Lisa McClain | Sell | $1K – $15K | PDF ↗ |
| 2025-08-04 | Lisa McClain | Buy | $1K – $15K | PDF ↗ |
Who owns MKSI
15 super-investors · 2025Q4
Tracked stake
8.65M
shares
Combined value
$943M
% of shares outstanding
—
shares-out unknown
Quarter action mix
New4Added6Trim5
| # | Manager | Shares | Value |
|---|---|---|---|
| 1 | Wellington Management | 2.55M | $408M |
| 2 | Norges Bank Norway SWF | 922.7K | $147M |
| 3 | Izzy Englander Millennium Mgmt | 817.3K | $131M |
| 4 | Steve Cohen Point72 | 625.8K | $100M |
| 5 | Ken Griffin Citadel Advisors | 457.9K | $73M |
| 6 | AQR Capital Management | 196.7K | $31M |
| 7 | Paul Tudor Jones Tudor Investment | 104.5K | $17M |
| 8 | Larry Robbins Glenview Capital | 74.2K | $12M |
| 9 | Ken Griffin Citadel Advisors | 44.8K | $7M |
| 10 | Ken Griffin Citadel Advisors | 43.8K | $7M |
| 11 | Two Sigma Investments | 29.4K | $5M |
| 12 | Glen Kacher Light Street Capital | 19.6K | $3M |
| 13 | Paul Tudor Jones Tudor Investment | 7.3K | $1M |
| 14 | Mario Gabelli GAMCO | 3.9K | $621K |
| 15 | T. Rowe Price | 2.75M | $440K |
Recent moves
20 transactions
- −461,774 · 2025Q4
- +26,665 · 2025Q4
- +104,482 · 2025Q4
- −387,754 · 2025Q4
- +316,715 · 2025Q4
- +371,003 · 2025Q4
- +19,582 · 2025Q4
- −97,722 · 2025Q4
- +23,158 · 2025Q4
- TRIMT. Rowe Price−879,169 · 2025Q4
- +922,737 · 2025Q4
- −4,000 · 2025Q4
- +1,013,553 · 2025Q3
- TRIMT. Rowe Price−496,109 · 2025Q3
- +441,432 · 2025Q3
- +1,400 · 2025Q3
- SOLDD.E. Shaw & Co.−96,288 · 2025Q3
- +14,341 · 2025Q3
- −60,374 · 2025Q3
- −15,050 · 2025Q3
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