MKSI MKS (MKSI) Insider Trading, Ownership & Congress Trades
Industrials · Industrial instruments for measurement, display, and control · CIK 0001049502
Congress · 1Form 144 · 3
Insider buyers, 180 days
0
Funds added, last quarter
460
13F, latest reported quarter
What the filings say about MKSI
Insiders, 180 days
-$25.0M net sold
13 sellers · 4% of sales under a 10b5-1 plan
Congress, 1 year
1 bought · 1 sold
Latest: sale, 2025-10-31
Planned sales (Form 144), 90 days
$3.2M
3 notices
MKS insider trades (Form 4)
Form 4 buys and sells (codes P and S). Grants, option exercises
and conversions excluded.
Over the last 180 days, MKS INC insiders sold a net $25.0M of stock across 100 Form 4 purchases and sales, with no insider buying. Source: SEC Form 4 filings, as of 2026-10-28.
Insider
Filed
Shares
Value
Since filing
Context
- 20 earlier Form 4 trades (code P or S) here by this insider (20 sales), the last on Jun 1, 2026.
- The trade is 1.6% of the 18,845 shares held after it.
- 2 other insiders sold within 30 days.
- 460 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Director Mora Elizabeth sold about $75.3K of MKSI under a 10b5-1 plan on Sep 1, 2026; 2 other insiders sold within 30 days and 460 funds added in the latest 13F quarter.Context
- 5 earlier Form 4 trades (code P or S) here by this insider (5 sales), the last on May 22, 2026.
- The trade is 7.4% of the 134,776 shares held after it.
- 2 other insiders sold within 30 days.
- 460 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: President & CEO Lee John Tseng-Chung sold about $3.0M of MKSI on Aug 14, 2026; 2 other insiders sold within 30 days and 460 funds added in the latest 13F quarter.Context
- 2 earlier Form 4 trades (code P or S) here by this insider (2 sales), the last on Feb 20, 2026.
- The trade is 11.2% of the 4,097 shares held after it.
- 2 other insiders sold within 30 days.
- 460 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: EVP & GM, PSD Williams John Edward sold about $131.8K of MKSI on Aug 3, 2026; 2 other insiders sold within 30 days and 460 funds added in the latest 13F quarter.Context
- 5 earlier Form 4 trades (code P or S) here by this insider (5 sales), the last on Jun 10, 2026.
- The trade is 4.2% of the 19,418 shares held after it.
- 9 other insiders sold within 30 days.
- 460 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: EVP & COO Schreiner James Alan sold about $281.3K of MKSI on Jun 12, 2026; 9 other insiders sold within 30 days and 460 funds added in the latest 13F quarter.Context
- 5 earlier Form 4 trades (code P or S) here by this insider (5 sales), the last on Jun 10, 2026.
- The trade is 12.2% of the 20,230 shares held after it.
- 9 other insiders sold within 30 days.
- 460 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: EVP & COO Schreiner James Alan sold about $853.8K of MKSI on Jun 12, 2026; 9 other insiders sold within 30 days and 460 funds added in the latest 13F quarter.100 transactions on record
Since filing: total return from the first close after the filing to the latest close, dividend-adjusted. Not a forecast.
Context lines are counts over the filings above and returns from our own price history, never a price level. Not investment advice.
Seven facts, ranked against the sector ·
Rank is not a forecast
Insiders
net -$25.0M over 180 days
-$3.2M over 90 days
below 88% of Industrials
Congress
1 member bought in the last year
the lowest in Industrials
Funds
460 funds bought in last quarter
more than 86% of Industrials
Revenue
+9.6% year over year
more than 66% of Industrials
Margin
7.5% net margin
more than 61% of Industrials
Buybacks
$45.0M repurchased, FY to 2025-12-31
below 52% of Industrials
Short interest
7.6% of the float short (float per yahoo 2026-10-26) · 4.2 days to cover · settled 2026-09-30
more than 84% of Industrials
What changed in the last 30 days
Nothing new filed in the last 30 days
Watch MKSI
A free account keeps a watchlist and can send one email a day when insiders, funds or Congress file on the names in it. No password and no card.
The year, with the filings on it
Total return over 12 months. Each marker is a filing; hover or tap one for the detail.
+44.3%12M
Insider sellForm 144 (planned sale)
Indexed to 100, dividend-adjusted, not a price chart.
When a name files heavily, the largest trades are drawn first.
Who owns MKSI: institutional holders (13F)
13F holdings, latest reported quarter
6,930,030 sh
$3.1B
4,661,664 sh
$2.1B
3,707,327 sh
$1.6B
3,373,844 sh
$1.4B
3,049,560 sh
$1.4B
Congress trades in MKSI
STOCK Act disclosures, US House only, filed up to 45 days after the trade
Sold 2025-10-31 · disclosed 21 days later
$1,001 - $15,000
Sold 2025-10-30 · disclosed 22 days later
$1,001 - $15,000
Bought 2025-10-30 · disclosed 22 days later
$1,001 - $15,000
Bought 2025-08-04 · disclosed 39 days later
$1,001 - $15,000
Activist and 5% holders (13D/13G)
No 5%+ ownership filings
Nobody has filed for crossing 5%. That is a fact, not missing data.
MKSI planned insider sales (Form 144)
Notice of intent to sell, filed before any sale
Mora Elizabeth
Filed 2026-09-01
$75.3K
Lee John Tseng-Chung
Filed 2026-08-14
$3.0M
Williams John Edward
Filed 2026-08-03
$131.8K
MKSI mutual fund holders (N-PORT)
Funds ranked by the share of their own portfolio in this stock (N-PORT).
ICON HEALTH AND INFORMATION TECHNOLOGY FUND
$8.0M position · as of 2026-06-30
8.2%
Spear Alpha ETF
$19.8M position · as of 2026-06-30
6.8%
Archer Stock Fund
$1.3M position · as of 2026-05-31
5.0%
Royce Premier Fund
$51.9M position · as of 2026-06-30
4.5%
Invesco V.I. American Value Fund
$20.1M position · as of 2026-06-30
4.2%
Marsico Midcap Growth Focus Fund
$39.2M position · as of 2026-06-30
4.2%
SEC N-PORT, monthly, about 60 days late · funds ≥ $10M ·
% is the share of the fund's own portfolio
Executive pay vs shareholder return
CEO pay, headline and as actually paid, against the company's
return and its chosen peers' (DEF 14A).
FY
CEO total
Actually paid
Other execs, avg
TSR
Peer TSR
2025
$13.0M
$25.0M
$2.8M
+10%
+105%
2024
$8.8M
$7.4M
$2.0M
-28%
+42%
2023
$7.9M
$13.2M
$2.1M
-30%
+22%
2022
$8.1M
$3.5M
$2.0M
-43%
+1%
2021
$7.6M
$11.4M
$2.3M
+16%
+29%
Tagged by the company under SEC Item 402(v). Returns are
cumulative from the start of the disclosure period. Green where the company beat its own peer group.
Live price
Daily candles from TradingView, under their licence. No filings marked.
Why this name is on the desk
Insiders have filed to sell, before selling.
The record shows a net $25.0M sold by insiders over 180 days, 460 funds added last quarter, 1 House member(s) bought in 12 months, disclosed weeks after the trade, $3.2M in planned Form 144 sales. Each figure is a federal filing, dated the day it went public.
MKSI financials
Revenue growth
+9.6%
XBRL, annual
Net margin
7.5%
Ratios from the company's XBRL filings, latest filings
Revenue, TTM
$4.3B
four quarters, 2025-07-01 to 2026-06-30
Revenue, TTM MKSI
| FY Dec 2025 | $3.9B |
| FY Dec 2024 | $3.6B |
| FY Dec 2023 | $3.6B |
| FY Dec 2022 | $3.5B |
| FY Dec 2021 | $3.0B |
| Jun 2026 | $1.2B |
| Mar 2026 | $1.1B |
| Dec 2025 | $1.0B |
| Sep 2025 | $988.0M |
| Jun 2025 | $973.0M |
| Mar 2025 | $936.0M |
| Dec 2024 | $934.0M |
| Sep 2024 | $896.0M |
At each fiscal year end
Single quarter
Net margin, TTM
+10.1%
net income over revenue, 2025-07-01 to 2026-06-30
Net margin, TTM MKSI
| FY Dec 2025 | +7.5% |
| FY Dec 2024 | n/a |
| FY Dec 2023 | -50.8% |
| FY Dec 2022 | +9.4% |
| FY Dec 2021 | +18.6% |
| Jun 2026 | +14.0% |
| Mar 2026 | +7.8% |
| Dec 2025 | +10.4% |
| Sep 2025 | +7.5% |
| Jun 2025 | +6.4% |
| Mar 2025 | +5.6% |
| Dec 2024 | +9.7% |
| Sep 2024 | +6.9% |
At each fiscal year end
Single quarter
Free cash flow, TTM
$455.0M
operating cash flow minus capex, 2025-07-01 to 2026-06-30
Free cash flow, TTM MKSI
| FY Dec 2025 | $497.0M |
| FY Dec 2024 | $410.0M |
| FY Dec 2023 | $232.0M |
| FY Dec 2022 | $365.0M |
| FY Dec 2021 | n/a |
| Jun 2026 | $189.0M |
| Mar 2026 | $28.0M |
| Dec 2025 | $92.0M |
| Sep 2025 | $146.0M |
| Jun 2025 | $136.0M |
| Mar 2025 | $123.0M |
| Dec 2024 | $125.0M |
| Sep 2024 | $141.0M |
At each fiscal year end
Single quarter
Debt to equity
1.32x
long-term 2026-06-30 plus current 2026-06-30; equity 2026-06-30
Debt to equity MKSI
| FY Dec 2025 | 1.55x |
| FY Dec 2024 | 1.95x |
| FY Dec 2023 | 2.04x |
| FY Dec 2022 | 1.16x |
| FY Dec 2021 | 0.29x |
| Jun 2026 | 1.32x |
| Mar 2026 | 1.44x |
| Dec 2025 | 1.55x |
| Sep 2025 | 1.66x |
| Jun 2025 | 1.73x |
| Mar 2025 | 1.89x |
| Dec 2024 | 1.95x |
| Sep 2024 | 2.01x |
At each fiscal year end
Trailing four quarters at each quarter end
Cash flow to debt
0.16x
TTM operating cash flow over long-term 2026-06-30 plus current 2026-06-30
Cash flow to debt MKSI
| FY Dec 2025 | 0.15x |
| FY Dec 2024 | 0.12x |
| FY Dec 2023 | 0.06x |
| FY Dec 2022 | 0.10x |
| FY Dec 2021 | 0.77x |
| Jun 2026 | 0.16x |
| Mar 2026 | 0.14x |
| Dec 2025 | 0.15x |
| Sep 2025 | 0.16x |
| Jun 2025 | 0.15x |
| Mar 2025 | 0.14x |
| Dec 2024 | 0.12x |
| Sep 2024 | 0.11x |
At each fiscal year end
Trailing four quarters at each quarter end
Return on equity
+15.9%
TTM net income over average of 2025-06-30 and 2026-06-30
Return on equity MKSI
| FY Dec 2025 | +11.7% |
| FY Dec 2024 | n/a |
| FY Dec 2023 | -52.9% |
| FY Dec 2022 | +9.0% |
| FY Dec 2021 | +21.0% |
| Jun 2026 | +15.9% |
| Mar 2026 | +12.7% |
| Dec 2025 | +11.7% |
| Sep 2025 | n/a |
| Jun 2025 | n/a |
| Mar 2025 | n/a |
| Dec 2024 | n/a |
| Sep 2024 | +1.3% |
At each fiscal year end
Trailing four quarters at each quarter end
Return on assets
+5.0%
TTM net income over average of 2025-06-30 and 2026-06-30
Return on assets MKSI
| FY Dec 2025 | +3.4% |
| FY Dec 2024 | n/a |
| FY Dec 2023 | -17.9% |
| FY Dec 2022 | +4.2% |
| FY Dec 2021 | +13.0% |
| Jun 2026 | +5.0% |
| Mar 2026 | +3.8% |
| Dec 2025 | +3.4% |
| Sep 2025 | n/a |
| Jun 2025 | n/a |
| Mar 2025 | n/a |
| Dec 2024 | n/a |
| Sep 2024 | +0.3% |
At each fiscal year end
Trailing four quarters at each quarter end
Return on invested capital
+9.8%
operating income after a 9.8% effective tax rate, over long-term 2026-06-30 plus current 2026-06-30 plus average of 2025-06-30 and 2026-06-30 minus cash
Return on invested capital MKSI
| FY Dec 2025 | +8.1% |
| FY Dec 2024 | n/a |
| FY Dec 2023 | n/a |
| FY Dec 2022 | +5.6% |
| FY Dec 2021 | +18.9% |
| Jun 2026 | +9.8% |
| Mar 2026 | +8.6% |
| Dec 2025 | +8.1% |
| Sep 2025 | n/a |
| Jun 2025 | n/a |
| Mar 2025 | n/a |
| Dec 2024 | n/a |
| Sep 2024 | n/a |
At each fiscal year end
Trailing four quarters at each quarter end
Return on capital employed
+9.4%
operating income (EBIT proxy) over average of 2025-06-30 and 2026-06-30 minus current liabilities
Return on capital employed MKSI
| FY Dec 2025 | +6.7% |
| FY Dec 2024 | +6.2% |
| FY Dec 2023 | -16.5% |
| FY Dec 2022 | +8.4% |
| FY Dec 2021 | +18.4% |
| Jun 2026 | +9.4% |
| Mar 2026 | +8.0% |
| Dec 2025 | +6.7% |
| Sep 2025 | +6.4% |
| Jun 2025 | +6.3% |
| Mar 2025 | +6.3% |
| Dec 2024 | +6.2% |
| Sep 2024 | +4.7% |
At each fiscal year end
Trailing four quarters at each quarter end
P/E, trailing
32.21x
close 2026-10-26 over four quarters of diluted EPS, 2025-07-01 to 2026-06-30
P/E, trailing MKSI
| FY Dec 2025 | 36.48x |
| FY Dec 2024 | 37.15x |
| FY Dec 2023 | n/a |
| FY Dec 2022 | 14.86x |
| FY Dec 2021 | 17.59x |
| Jun 2026 | 70.83x |
| Mar 2026 | 47.98x |
| Dec 2025 | 36.48x |
| Sep 2025 | 29.97x |
| Jun 2025 | 25.15x |
| Mar 2025 | 23.85x |
| Dec 2024 | 37.15x |
| Sep 2024 | 236.33x |
At each fiscal year end
Trailing four quarters at each quarter end
Enterprise value
$17.2B
market value at close 2026-10-26 on 2026-07-28 shares, plus long-term 2026-06-30 plus current 2026-06-30, minus cash 2026-06-30
Enterprise value MKSI
| FY Dec 2025 | $14.5B |
| FY Dec 2024 | $11.1B |
| FY Dec 2023 | $11.4B |
| FY Dec 2022 | $10.5B |
| FY Dec 2021 | $10.1B |
| Jun 2026 | $33.5B |
| Mar 2026 | $19.0B |
| Dec 2025 | $14.5B |
| Sep 2025 | $12.2B |
| Jun 2025 | $10.6B |
| Mar 2025 | $9.5B |
| Dec 2024 | $11.1B |
| Sep 2024 | $11.7B |
At each fiscal year end
Trailing four quarters at each quarter end
FCF yield
+3.3%
TTM free cash flow over market value at close 2026-10-26
FCF yield MKSI
| FY Dec 2025 | +4.6% |
| FY Dec 2024 | +5.8% |
| FY Dec 2023 | +3.4% |
| FY Dec 2022 | +6.5% |
| FY Dec 2021 | n/a |
| Jun 2026 | +1.5% |
| Mar 2026 | +2.6% |
| Dec 2025 | +4.6% |
| Sep 2025 | +6.4% |
| Jun 2025 | +7.9% |
| Mar 2025 | +9.0% |
| Dec 2024 | +5.8% |
| Sep 2024 | +5.9% |
At each fiscal year end
Trailing four quarters at each quarter end
PEG, trailing
0.55x
P/E over trailing EPS growth of 59%: four quarters to 2026-06-30 against the four to 2025-06-30
PEG, trailing MKSI
| FY Dec 2025 | 0.65x |
| FY Dec 2024 | n/a |
| FY Dec 2023 | n/a |
| FY Dec 2022 | n/a |
| FY Dec 2021 | 0.31x |
| Jun 2026 | 1.20x |
| Mar 2026 | 1.13x |
| Dec 2025 | 0.65x |
| Sep 2025 | 0.04x |
| Jun 2025 | 0.01x |
| Mar 2025 | n/a |
| Dec 2024 | n/a |
| Sep 2024 | n/a |
At each fiscal year end
Trailing four quarters at each quarter end
Price as of 2026-10-26. Hover or tap a tile for its yearly and quarterly history.
Method
TTM is four consecutive fiscal quarters; Q4 is the year minus nine months when not filed. Returns use the average of opening and closing balances. EBIT is approximated by operating income. PEG uses trailing EPS growth.
Fundamentals
Annual figures from XBRL filings. Pick a past date to see them as known then.
| 2025-12 | 2024-12 | 2023-12 | 2022-12 | |
|---|---|---|---|---|
| Revenue | $3.9B | $3.6B | $3.6B | $3.5B |
| Gross profit | $1.8B | $1.7B | $1.6B | $1.5B |
| Operating income | $528.0M | $498.0M | -$1.6B | $617.0M |
| Net income | $295.0M | $190.0M | -$1.8B | $333.0M |
| EPS (diluted) | 4.37 | 2.81 | -27.54 | 5.56 |
| Operating cash flow | $645.0M | $528.0M | $319.0M | $529.0M |
| Cash | $418.0M | $420.0M | $507.0M | n/a |
| Long-term debt | $4.2B | $4.5B | $5.0B | $5.1B |
| Buybacks | $45.0M | $0 | $0 | n/a |
| Dividends paid | $59.0M | $59.0M | $59.0M | $52.0M |
SEC XBRL, fiscal years, as known on 2026-10-28
MKSI Stock Sonar score 6/7 axes
Find similar shapesCompareMKSI ranks highest on institutional and government (71st percentile) and growth (66th), and lowest on insider conviction (6th), among Industrials peers.
6 of 7 axes scored. Each is a percentile against sector peers (all companies when the sector is thin); higher is better. An unscored axis is unmeasured, not low. How it is scored
MKSI filings, in plain words
Are MKS insiders buying or selling MKSI?
In the 180 days to 2026-10-28, MKS insiders were net sellers, a net $25.0M across purchases and sales reported on Form 4, by 13 sellers.
Have members of Congress traded MKSI?
Yes. In the year to 2026-10-28, 1 House member disclosed buying MKSI and 1 House member disclosed selling it; the latest on record is a sale by Lisa McClain dated 2025-10-31.
Are there planned insider sales of MKSI?
Yes. 3 Form 144 notices of planned insider sales were filed in the 90 days to 2026-10-28, covering $3.2M of stock; the latest, by Mora Elizabeth, was filed 2026-09-01.
Read the full summary
In the 180 days to 2026-10-28, MKS insiders were net sellers of MKSI, a net $25.0M across purchases and sales reported on Form 4 by 13 sellers. 4% of the 26 insider sales were made under a Rule 10b5-1 plan; the rest were not flagged as planned. In the year to 2026-10-28, 1 member of Congress disclosed buying MKSI and 1 member disclosed selling it; the latest on record is a sale by Lisa McClain dated 2025-10-31. Insiders filed 3 Form 144 notices of intent to sell in the 90 days to 2026-10-28, covering $3.2M of stock. Each figure is counted from SEC and House filings as of 2026-10-28, dated the day the filing was made public.
Explore insider trading and ownership data
Every company we track, ranked by each kind of filing
