MKS INC. MKSI
COM · Common Stock · CUSIP 55306N104 · ISIN US55306N1046
Company in Andover, United States
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($84.2m this quarter). Holder counts are more reliable. Shares outstanding: 67.6m as of 2026-07-28, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $442.16. Options: 19 managers hold calls ($2.2bn notional), 19 hold puts ($325.8m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 357 |
| Q4 2022 | 316 |
| Q1 2023 | 325 |
| Q2 2023 | 321 |
| Q3 2023 | 324 |
| Q4 2023 | 325 |
| Q1 2024 | 343 |
| Q2 2024 | 397 |
| Q3 2024 | 410 |
| Q4 2024 | 419 |
| Q1 2025 | 399 |
| Q2 2025 | 397 |
| Q3 2025 | 435 |
| Q4 2025 | 516 |
| Q1 2026 | 621 |
| Q2 2026 | 774 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 244 | 163 |
| Q4 2024 | 215 | 181 |
| Q1 2025 | 223 | 197 |
| Q2 2025 | 224 | 205 |
| Q3 2025 | 225 | 176 |
| Q4 2025 | 284 | 185 |
| Q1 2026 | 354 | 244 |
| Q2 2026 | 447 | 304 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $261.2m | $44.3m | 0.17 |
| Q4 2025 | $339.9m | $58.0m | 0.17 |
| Q1 2026 | $496.0m | $50.6m | 0.10 |
| Q2 2026 | $2.2bn | $325.8m | 0.15 |
Biggest buyers
| JPMORGAN CHASE & CO | Added | +1.3m |
| ALKEON CAPITAL MANAGEMENT LLC | New | +1.1m |
| Invesco Ltd. | Added | +940.2k |
| Sachem Head Capital Management LP | New | +812.7k |
| Qube Research & Technologies Ltd | Added | +531.7k |
| Point72 Asset Management, L.P. | Added | +386.5k |
| TOMS Capital Investment Management LP | New | +293.0k |
| BlackRock, Inc. | Added | +288.3k |
| Aspex Management (HK) Ltd | Added | +281.7k |
| PRICE T ROWE ASSOCIATES INC /MD/ | Added | +189.8k |
Biggest sellers
| FMR LLC | Reduced | -434.3k |
| WELLINGTON MANAGEMENT GROUP LLP | Reduced | -417.1k |
| FRANKLIN RESOURCES INC | Reduced | -390.2k |
| Contour Asset Management LLC | Sold out | -374.9k |
| DIMENSIONAL FUND ADVISORS LP | Reduced | -302.2k |
| AMERICAN CENTURY COMPANIES INC | Reduced | -275.4k |
| VICTORY CAPITAL MANAGEMENT INC | Reduced | -269.7k |
| NEUBERGER BERMAN GROUP LLC | Reduced | -268.5k |
| CITADEL ADVISORS LLC | Reduced | -249.4k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -249.3k |
Biggest calls
| JANE STREET GROUP, LLC | Added | $646.1m1.5m shares |
| UBS Group AG | Added | $505.3m1.1m shares |
| NOMURA HOLDINGS INC | Added | $444.8m1.0m shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $329.8m741.4k shares |
| PEAK6 LLC | Added | $111.0m249.6k shares |
| SG Americas Securities, LLC | New | $72.1m220.0k shares |
| Caption Management, LLC | Added | $64.5m145.0k shares |
| CITADEL ADVISORS LLC | Added | $38.8m87.3k shares |
| IMC-Chicago, LLC | Added | $13.0m29.2k shares |
| Squarepoint Ops LLC | Added | $4.0m9.1k shares |
Biggest puts
| JANE STREET GROUP, LLC | Added | $173.5m390.1k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $38.3m86.1k shares |
| CITADEL ADVISORS LLC | Added | $29.0m65.3k shares |
| NOMURA HOLDINGS INC | Added | $24.0m54.0k shares |
| IMC-Chicago, LLC | Added | $18.5m41.7k shares |
| PEAK6 LLC | Unchanged | $16.7m37.5k shares |
| Squarepoint Ops LLC | Added | $7.4m16.6k shares |
| SG Americas Securities, LLC | New | $7.2m220.0k shares |
| Oribel Capital Management, LP | New | $3.7m8.3k shares |
| Walleye Trading LLC | Reduced | $1.5m3.4k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| BlackRock, Inc. 13G · institution filed 2025-10-17 | 8.8% |
| Invesco Ltd. 13G · institution new · filed 2026-02-12 | 6.5% |
| VANGUARD PORTFOLIO MANAGEMENT LLC 13G · institution new · filed 2026-04-29 | 5.5% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-30 | 5.2% |
Fell to 5% or below in the last year: JPMORGAN CHASE & CO (2.9%, 2026-09-03), VICTORY CAPITAL MANAGEMENT INC (90.0%, 2026-07-24), FMR LLC (3.3%, 2026-05-06), VANGUARD GROUP INC (0.0%, 2026-03-27; now reported by VANGUARD PORTFOLIO MANAGEMENT LLC), PRICE T ROWE ASSOCIATES INC /MD/ (4.1%, 2026-02-17)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 2 | $92.9k | $92.9k |
| Q1 2025 | 0 | — | 3 | $889.4k | $53.2k |
| Q2 2025 | 0 | — | 1 | $24.5k | $24.5k |
| Q3 2025 | 0 | — | 4 | $1.1m | $1.1m |
| Q4 2025 | 0 | — | 3 | $182.9k | $182.9k |
| Q1 2026 | 0 | — | 11 | $18.3m | $71.8k |
| Q2 2026 | 0 | — | 12 | $21.8m | $14.5m |
| Q3 2026 | 0 | — | 3 | $3.2m | $3.2m |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-09-01 | Mora Elizabeth Director | Sold plan | $75.3k300 shares |
| 2026-08-14 | Lee John Tseng-Chung President & CEO, director | Sold plan | $3.0m10.0k shares |
| 2026-08-03 | Williams John Edward EVP & GM, PSD | Sold plan | $131.8k457 shares |
| 2026-06-12 | Schreiner James Alan EVP & COO | Sold | $1.2m3.5k shares |
| 2026-06-10 | Schreiner James Alan EVP & COO | Sold plan | $247.9k781 shares |
| 2026-06-05 | McCarthy Michelle M SVP & Chief Accounting Officer | Sold plan | $767.3k2.4k shares |
| 2026-06-01 | Henry David Philip EVP, Global Str Mktg & GM, MSD | Sold | $1.9m6.0k shares |
| 2026-06-01 | Mora Elizabeth Director | Sold plan | $95.4k300 shares |
| 2026-05-27 | COLELLA GERALD G Director · By The Gerald G. Colella 2019 Trust | Sold plan | $6.7m20.0k shares |
| 2026-05-27 | Donahue Joseph B Director | Sold | $688.7k2.1k shares |
| 2026-05-26 | Henry David Philip EVP, Global Str Mktg & GM, MSD | Sold plan | $826.2k2.5k shares |
| 2026-05-22 | Lee John Tseng-Chung President & CEO, director | Sold plan | $3.2m10.0k shares |
| 2026-05-22 | Mayampurath Ramakumar EVP & CFO | Sold plan | $2.8m8.8k shares |
| 2026-05-18 | CANNONE PETER III Director | Sold | $409.6k1.4k shares |
| 2026-05-14 | Moloney Jacqueline F Director | Sold | $312.2k1.0k shares |
| 2026-05-13 | Moloney Jacqueline F Director | Sold | $446.6k1.4k shares |
| 2026-05-11 | Burke Kathleen Flaherty EVP, GC & Secretary | Sold | $1.4m4.4k shares |
| 2026-05-11 | Taranto Eric Robert EVP & GM, VSD | Sold | $911.3k2.8k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| BlackRock, Inc. 0.05% of their portfolio | 6.9m $3.1bn | Added +288.3k |
| Invesco Ltd. 0.16% of their portfolio | 4.7m $2.1bn | Added +940.2k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.07% of their portfolio | 3.7m $1.6bn | Added +21.8k |
| JPMORGAN CHASE & CO 0.08% of their portfolio | 3.4m $1.4bn | Added +1.3m |
| VANGUARD CAPITAL MANAGEMENT LLC 0.03% of their portfolio | 3.0m $1.4bn | Added +35.4k |
| STATE STREET CORP 0.03% of their portfolio | 2.1m $949.4m | Added +76.9k |
| Point72 Asset Management, L.P. 1.36% of their portfolio | 2.0m $888.2m | Added +386.5k |
| Capital International Investors 0.18% of their portfolio | 1.9m $851.9m | Reduced -53.6k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.08% of their portfolio | 1.9m $840.6m | Added +189.8k |
| Aspex Management (HK) Ltd 9.13% of their portfolio | 1.8m $809.7m | Added +281.7k |
| GEODE CAPITAL MANAGEMENT, LLC 0.04% of their portfolio | 1.5m $686.6m | Reduced -247 |
| FMR LLC 0.03% of their portfolio | 1.5m $667.0m | Reduced -434.3k |
| WELLINGTON MANAGEMENT GROUP LLP 0.11% of their portfolio | 1.4m $629.9m | Reduced -417.1k |
| Capital World Investors 0.07% of their portfolio | 1.4m $607.7m | Added +89.1k |
| Whale Rock Capital Management LLC 4.54% of their portfolio | 1.3m $565.5m | Reduced -35.4k |
| NEUBERGER BERMAN GROUP LLC 0.35% of their portfolio | 1.2m $518.2m | Reduced -268.5k |
| ALKEON CAPITAL MANAGEMENT LLC 1.84% of their portfolio | 1.1m $476.8m | New |
| NORGES BANK 0.04% of their portfolio | 954.7k $424.6m | Not comparable |
| WESTFIELD CAPITAL MANAGEMENT CO LP 1.35% of their portfolio | 928.6k $413.0m | Reduced -118.1k |
| Sachem Head Capital Management LP 7.50% of their portfolio | 812.7k $361.5m | New |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.05% of their portfolio | 808.2k $359.5m | Reduced -58.4k |
| CITADEL ADVISORS LLC 0.18% of their portfolio | 697.7k $310.3m | Reduced -249.4k |
| MORGAN STANLEY 0.02% of their portfolio | 681.6k $303.2m | Added +166.5k |
| Bank of New York Mellon Corp 0.05% of their portfolio | 658.5k $292.9m | Reduced -173.6k |
| MILLENNIUM MANAGEMENT LLC 0.19% of their portfolio | 645.1k $286.9m | Reduced -249.3k |
| AQR CAPITAL MANAGEMENT LLC 0.10% of their portfolio | 638.3k $280.2m | Added +21.8k |
| VICTORY CAPITAL MANAGEMENT INC 0.15% of their portfolio | 609.0k $270.9m | Reduced -269.7k |
| Qube Research & Technologies Ltd 0.30% of their portfolio | 606.1k $269.6m | Added +531.7k |
| FengHe Fund Management Pte. Ltd. 24.54% of their portfolio | 581.7k $258.7m | Added +125.4k |
| NORTHERN TRUST CORP 0.03% of their portfolio | 577.9k $257.0m | Added +8.6k |
| DIMENSIONAL FUND ADVISORS LP 0.04% of their portfolio | 533.1k $237.0m | Reduced -302.2k |
| BANK OF AMERICA CORP /DE/ 0.01% of their portfolio | 520.8k $231.7m | Added +57.1k |
| PRINCIPAL FINANCIAL GROUP INC 0.10% of their portfolio | 474.7k $211.1m | Reduced -139.5k |
| VANGUARD FIDUCIARY TRUST CO 0.04% of their portfolio | 428.2k $190.4m | Added +11.0k |
| GOLDMAN SACHS GROUP INC 0.02% of their portfolio | 361.7k $160.9m | Added +116.1k |
| Nuveen, LLC 0.04% of their portfolio | 361.4k $160.8m | Reduced -16.7k |
| RAYMOND JAMES FINANCIAL INC 0.04% of their portfolio | 327.4k $145.6m | Reduced -10.5k |
| UBS Group AG 0.02% of their portfolio | 321.7k $143.1m | Reduced -110.4k |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC 3.70% of their portfolio | 319.8k $142.3m | Added +37.6k |
| Madison Asset Management, LLC 1.68% of their portfolio | 316.7k $140.9m | Reduced -21.6k |
| TREMBLANT CAPITAL GROUP 3.77% of their portfolio | 295.4k $131.4m | Reduced -34.4k |
| TOMS Capital Investment Management LP 6.88% of their portfolio | 293.0k $130.3m | New |
| TimesSquare Capital Management, LLC 1.89% of their portfolio | 288.4k $128.3m | Added +285 |
| SAMLYN CAPITAL, LLC 2.08% of their portfolio | 281.9k $125.4m | Reduced -214.8k |
| ALLIANCEBERNSTEIN L.P. 0.02% of their portfolio | 275.7k $63.4m | Reduced -44.2k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.09% of their portfolio | 265.5k $118.1m | Reduced -134.8k |
| ROYCE & ASSOCIATES LP 0.94% of their portfolio | 261.6k $116.3m | Reduced -142.1k |
| Polar Capital Holdings Plc 0.33% of their portfolio | 260.4k $115.8m | Added +188.2k |
| Balyasny Asset Management L.P. 0.21% of their portfolio | 260.2k $115.7m | Reduced -147.2k |
| NATIXIS ADVISORS, LLC 0.13% of their portfolio | 260.2k $115.7m | Added +28.2k |
| JONES FINANCIAL COMPANIES LLLP 0.04% of their portfolio | 250.6k $97.4m | Added +26.8k |
| Amundi 0.03% of their portfolio | 241.7k $107.5m | Reduced -13.1k |
| NORDEA INVESTMENT MANAGEMENT AB 0.08% of their portfolio | 232.1k $102.5m | Reduced -94.2k |
| MARSHALL WACE, LLP 0.08% of their portfolio | 225.1k $100.1m | Added +126.4k |
| Quantinno Capital Management LP 0.12% of their portfolio | 223.2k $99.3m | Reduced -36.6k |
| WELLS FARGO & COMPANY/MN 0.02% of their portfolio | 216.6k $96.3m | Reduced -26.5k |
| Penserra Capital Management LLC 0.72% of their portfolio | 210.8k $93.8m | Reduced -39.8k |
| Defiance ETFs, LLC 1.20% of their portfolio | 210.4k $86.5m | Reduced -40.2k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.02% of their portfolio | 207.8k $92.4m | Added +3.8k |
| SYSTEMATIC FINANCIAL MANAGEMENT LP 1.70% of their portfolio | 192.0k $85.4m | Reduced -50.0k |
| RHUMBLINE ADVISERS 0.06% of their portfolio | 179.9k $80.0m | Reduced -70 |
| NORTHWESTERN MUTUAL WEALTH MANAGEMENT CO 0.04% of their portfolio | 173.2k $77.0m | Added +173.0k |
| Gotham Asset Management, LLC 0.18% of their portfolio | 170.2k $75.7m | Reduced -25.2k |
| COOKE & BIELER LP 0.85% of their portfolio | 165.2k $73.5m | Reduced -44.8k |
| Handelsbanken Fonder AB 0.21% of their portfolio | 164.5k $73.2m | Reduced -28.0k |
| Evergreen Quality Fund GP, Ltd. 1.18% of their portfolio | 164.2k $73.0m | New |
| VALUE HOLDINGS MANAGEMENT CO. LLC 11.85% of their portfolio | 159.5k $70.9m | Reduced -85.6k |
| FIRST TRUST ADVISORS LP 0.04% of their portfolio | 157.2k $69.9m | Added +105.2k |
| LPL Financial LLC 0.02% of their portfolio | 157.0k $69.8m | Reduced -18.0k |
| FEDERATED HERMES, INC. 0.10% of their portfolio | 149.7k $66.6m | Added +49.5k |
| Blue Grotto Capital, LLC 5.55% of their portfolio | 149.4k $66.5m | Reduced -225.6k |
| Retirement Systems of Alabama 0.20% of their portfolio | 146.0k $64.9m | Reduced -12.5k |
| TWO SIGMA INVESTMENTS, LP 0.05% of their portfolio | 143.4k $63.8m | Reduced -135.3k |
| Artemis Investment Management LLP 0.56% of their portfolio | 142.0k $63.2m | New |
| Harvey Partners, LLC 4.35% of their portfolio | 141.1k $62.7m | Reduced -102.3k |
| Park West Asset Management LLC 4.22% of their portfolio | 138.7k $61.7m | Reduced -110.5k |
| Swiss National Bank 0.03% of their portfolio | 136.4k $60.7m | Added +3.5k |
| Rockefeller Capital Management L.P. 0.09% of their portfolio | 135.4k $60.2m | Added +134.1k |
| TORONTO DOMINION BANK 0.10% of their portfolio | 134.9k $60.0m | Added +96.2k |
| SummitTX Capital, L.P. 1.55% of their portfolio | 132.0k $58.7m | Reduced -28.9k |
| CRAMER ROSENTHAL MCGLYNN LLC 2.96% of their portfolio | 131.2k $58.4m | Reduced -17.2k |
| California Public Employees Retirement System 0.03% of their portfolio | 129.0k $57.4m | Added +5.7k |
| DENDUR CAPITAL LP 3.23% of their portfolio | 124.0k $55.2m | Reduced -90.5k |
| ROYAL BANK OF CANADA 0.01% of their portfolio | 122.9k $54.7m | Reduced -30.1k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.50% of their portfolio | 120.6k $53.7m | Reduced -40.6k |
| Spyglass Capital Management LLC 2.85% of their portfolio | 118.5k $52.7m | New |
| Legal & General Group Plc 0.01% of their portfolio | 117.8k $51.8m | Added +27.8k |
| BANK OF MONTREAL /CAN/ 0.02% of their portfolio | 117.8k $52.4m | Added +650 |
| BARCLAYS PLC 0.02% of their portfolio | 116.8k $52.0m | Reduced -44.7k |
| Thrivent Financial for Lutherans 0.09% of their portfolio | 113.9k $50.7m | Reduced -29.7k |
| Mizuho Markets Cayman LP 1.89% of their portfolio | 113.1k $50.3m | Reduced -61.9k |
| NEEDHAM INVESTMENT MANAGEMENT LLC 1.50% of their portfolio | 112.2k $49.9m | Reduced -7.8k |
| SORA INVESTORS LLC 3.67% of their portfolio | 107.5k $47.8m | Reduced -55.3k |
| LIGHT STREET CAPITAL MANAGEMENT, LLC 5.43% of their portfolio | 103.8k $46.2m | Reduced -18.5k |
| DEUTSCHE BANK AG\ 0.01% of their portfolio | 100.4k $44.7m | Reduced -32.6k |
| GLENVIEW CAPITAL MANAGEMENT, LLC 0.88% of their portfolio | 98.5k $43.8m | New |
| NOMURA HOLDINGS INC 0.18% of their portfolio | 96.8k $43.1m | Reduced -172.5k |
| ENVESTNET ASSET MANAGEMENT INC 0.01% of their portfolio | 95.4k $42.5m | Added +19.6k |
| LOOMIS SAYLES & CO L P 0.05% of their portfolio | 93.8k $41.7m | Reduced -33.4k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.27% of their portfolio | 91.4k $40.7m | Reduced -6.4k |