Stocks › MKSI
MKS INC
MKSI·Nasdaq·
United States·USD
United States·USD$281.41
+0.91 (+0.32%)
Close · Oct 6, 2026 · Close Prices from Tiingo.com
MKSI
MKS INC · Nasdaq
Nasdaq 100S&P 500
Filings
Default90D1Y5YALL
MKSIS&P 500 (rebased)
Congress BuyCongress SellInsider BuyInsider SellForm 1448-K ResultsLobbying
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Daily closes, adjusted for splits and dividends · Close Prices from Tiingo.comHover a marker, every one is a filing · move across the line for the crosshair
Congressional Trades
Recent trades of MKSI by members of U.S. Congress · 8 on record · 3 in the last 12 months
| Politician | Stock | Type | Filed | Traded | |
|---|---|---|---|---|---|
 Lisa C. McClainHouse · R · MI |
MKSIMKS INC · Stock |
Sale $1,001 - $15,000 |
Nov 21, 2025 | Oct 30, 2025 | Filing ↗ |
| Lisa C. McClainHouse · R · MI |
MKSIMKS INC · Stock |
Purchase $1,001 - $15,000 |
Nov 21, 2025 | Oct 30, 2025 | Filing ↗ |
| Lisa C. McClainHouse · R · MI |
MKSIMKS INC · Stock |
Sale $1,001 - $15,000 |
Nov 21, 2025 | Oct 31, 2025 | Filing ↗ |
| Lisa C. McClainHouse · R · MI |
MKSIMKS INC · Stock |
Purchase $1,001 - $15,000 |
Sep 12, 2025 | Aug 4, 2025 | Filing ↗ |
 Tommy TubervilleSenate · R · AL |
MKSIMKS INC · Stock |
Sale $1,001 - $15,000 |
May 12, 2023 | Apr 3, 2023 | Filing ↗ |
| Tommy TubervilleSenate · R · AL |
MKSIMKS INC · Stock |
Sale $1,001 - $15,000 |
May 11, 2023 | Apr 3, 2023 | Filing ↗ |
| Tommy TubervilleSenate · R · AL |
MKSIMKS INC · Stock |
Purchase $1,001 - $15,000 |
Apr 8, 2022 | Mar 30, 2022 | Filing ↗ |
 Nicholas Van TaylorHouse · R · TX |
MKSIMKS INC · Stock |
Sale $1,001 - $15,000 |
Apr 15, 2019 | Mar 25, 2019 | Filing ↗ |
Whale Activity
Position changes in MKSI reported for 2026-06-30 by 35 tracked institutional filers
- Increased6
- New1
- Held0
- Decreased7
- Closed0
- No prior filing21
| Filer | Shares | Value | Change |
|---|---|---|---|
| BlackRock, Inc. | 6.9M | $3.08B | increased |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 3.7M | $1.65B | increased |
| VANGUARD CAPITAL MANAGEMENT LLC | 3.0M | $1.36B | increased |
| Point72 Asset Management, L.P. | 2.0M | $888.2M | increased |
| WESTFIELD CAPITAL MANAGEMENT CO LP | 928.6K | $413.0M | — |
| Sachem Head Capital Management LP | 812.7K | $361.5M | — |
| CITADEL ADVISORS LLC | 697.7K | $310.3M | decreased |
| MILLENNIUM MANAGEMENT LLC | 645.1K | $286.9M | decreased |
| TOMS Capital Investment Management LP | 293.0K | $130.3M | — |
| SAMLYN CAPITAL, LLC | 281.9K | $125.4M | — |
| ROYCE & ASSOCIATES LP | 261.6K | $116.3M | — |
| Jain Global LLC | 38.8M | $114.3M | — |
KeyVex tracks a curated set of large 13F filers plus the largest positions in recent filings, so this is a sample of institutional activity, not the whole market.
Insider Trading
Net shares bought (+) or sold (−) on the open market by MKSI insiders, by quarter · Form 4
Recent Insider Transactions
2,442 transactions on record · newest first
| Insider | Type | Shares | Price | Value | Date | |
|---|---|---|---|---|---|---|
| Mora ElizabethDirector · Director | Sale | −300 | $250.96 | $75K | Sep 1, 2026 | Form 4 ↗ |
| Lee John Tseng-ChungPresident & CEO · Director | Sale | −10.0K | $302.01 | $3.0M | Aug 14, 2026 | Form 4 ↗ |
| Williams John EdwardEVP & GM, PSD | Sale | −457 | $288.31 | $132K | Aug 3, 2026 | Form 4 ↗ |
| Schreiner James AlanEVP & COO | Sale | −217 | $347.00 | $75K | Jun 12, 2026 | Form 4 ↗ |
| Schreiner James AlanEVP & COO | Sale | −812 | $346.41 | $281K | Jun 12, 2026 | Form 4 ↗ |
| Schreiner James AlanEVP & COO | Sale | −2,471 | $345.52 | $854K | Jun 12, 2026 | Form 4 ↗ |
| Schreiner James AlanEVP & COO | Sale | −781 | $317.42 | $248K | Jun 10, 2026 | Form 4 ↗ |
| McCarthy Michelle MSVP & Chief Accounting Officer | Sale | −2,434 | $315.23 | $767K | Jun 5, 2026 | Form 4 ↗ |
| Henry David PhilipEVP, Global Str Mktg & GM, MSD | Sale | −6,000 | $314.43 | $1.9M | Jun 1, 2026 | Form 4 ↗ |
| Mora ElizabethDirector | Sale | −300 | $318.02 | $95K | Jun 1, 2026 | Form 4 ↗ |
| Donahue Joseph BDirector | Sale | −2,100 | $327.95 | $689K | May 27, 2026 | Form 4 ↗ |
| COLELLA GERALD GDirector | Sale | −2,800 | $338.58 | $948K | May 27, 2026 | Form 4 ↗ |
| COLELLA GERALD GDirector | Sale | −213 | $337.05 | $72K | May 27, 2026 | Form 4 ↗ |
| COLELLA GERALD GDirector | Sale | −1,626 | $336.54 | $547K | May 27, 2026 | Form 4 ↗ |
| COLELLA GERALD GDirector | Sale | −1,811 | $335.46 | $608K | May 27, 2026 | Form 4 ↗ |
| COLELLA GERALD GDirector | Sale | −4,876 | $332.04 | $1.6M | May 27, 2026 | Form 4 ↗ |
| COLELLA GERALD GDirector | Sale | −8,210 | $331.45 | $2.7M | May 27, 2026 | Form 4 ↗ |
| COLELLA GERALD GDirector | Sale | −464 | $330.38 | $153K | May 27, 2026 | Form 4 ↗ |
| Henry David PhilipEVP, Global Str Mktg & GM, MSD | Sale | −2,500 | $330.50 | $826K | May 26, 2026 | Form 4 ↗ |
| Mayampurath RamakumarEVP & CFO | Sale | −8,810 | $315.48 | $2.8M | May 22, 2026 | Form 4 ↗ |
Fund Holders
Mutual funds and ETFs holding MKSI · SEC Form N-PORT
| Fund | Shares | Value | % of fund | As of |
|---|---|---|---|---|
| SMALLCAP World Fund Inc | 2.5M | $1.09B | 1.15% | Jun 30, 2026 |
| iShares Core S&P Mid-Cap ETF iShares Trust | 2.3M | $1.03B | 0.83% | Jun 30, 2026 |
| VANGUARD TOTAL STOCK MARKET INDEX FUND VANGUARD INDEX FUNDS | 2.1M | $953.6M | 0.04% | Jun 30, 2026 |
| VANGUARD SMALL-CAP INDEX FUND VANGUARD INDEX FUNDS | 1.5M | $688.9M | 0.37% | Jun 30, 2026 |
| JPMorgan Large Cap Growth Fund JPMorgan Trust II | 800.1K | $355.9M | 0.29% | Jun 30, 2026 |
| VANGUARD EXTENDED MARKET INDEX FUND VANGUARD INDEX FUNDS | 774.6K | $344.6M | 0.35% | Jun 30, 2026 |
| Invesco Small Cap Value Fund AIM Sector Funds (Invesco Sector Funds) | 1.1M | $341.0M | 3.07% | Jul 31, 2026 |
| Invesco Value Opportunities Fund AIM Sector Funds (Invesco Sector Funds) | 882.5K | $262.5M | 2.89% | Jul 31, 2026 |
| VANGUARD INFORMATION TECHNOLOGY INDEX FUND VANGUARD WORLD FUND | 763.0K | $247.4M | 0.14% | May 31, 2026 |
| JPMorgan Mid Cap Value Fund J.P. Morgan Fleming Mutual Fund Group, Inc. | 542.7K | $241.4M | 2.16% | Jun 30, 2026 |
Mutual funds and ETFs whose N-PORT filings list MKSI's shares (CUSIP 55306N104), each fund at its latest report since Mar 7, 2026, largest positions first. Bonds, options and short positions are left out.
Activist & Passive Stakes
Schedule 13D / 13G beneficial-ownership filings
- JPMORGAN CHASE & CO.SCHEDULE 13G/A · passive (13G) · 2.0M shares2.9%
Sep 3, 2026 · ↗ - Victory Capital Management, Inc.SCHEDULE 13G/A · passive (13G) · 604.7K shares0.9%
Jul 24, 2026 · ↗ - JPMORGAN CHASE & COSCHEDULE 13G · passive (13G) · 3.4M shares5.0%
Jul 16, 2026 · ↗ - Abigail P. JohnsonSCHEDULE 13G/A · passive (13G) · 2.2M shares3.3%
May 6, 2026 · ↗ - FMR LLCSCHEDULE 13G/A · passive (13G) · 2.2M shares3.3%
May 6, 2026 · ↗ - Vanguard Capital ManagementSCHEDULE 13G · passive (13G) · 3.5M shares5.2%
Apr 30, 2026 · ↗
Corporate Lobbying
Estimated quarterly lobbying spending reported under the LDA, filings naming MKS INC as client
No lobbying filings found naming MKS INC as the client.
Government Contracts
Federal awards to mks · USAspending
$36KAwarded · 2 contracts on record
U.S. Patents
Recent USPTO applications naming MKS INC
No USPTO patent applications found for MKS INC.
Annual Financials
From MKSI's 10-K filings · XBRL
No annual XBRL figures on record for MKSI. KeyVex's fundamentals cover about 130 large companies so far.
Stock Splits
Every split and reverse split in the price history
No stock splits in MKSI's price history.
About MKS INC
From SEC EDGAR company records
Industry (SIC 3823)Industrial Instruments For Measurement, Display, and Control
SectorTechnology
HeadquartersANDOVER, MA
IncorporatedMA
SEC CIK0001049502 ↗
Former namesMKS INSTRUMENTS INC