Kathleen Flaherty Burke
CIK 1775435 · View on SEC EDGAR ↗
Insider
First SEC filing: May 9, 2019 · Latest: May 9, 2019
On this page
- Insider at Companies where this person is a reporting insider.
- Insider transactions Every share this person bought or sold, from Form 4 filings.
- Derivatives Options and other derivative holdings reported by this person.
- Initial holdings The stakes this person held when they first started reporting.
- Compensation Executive pay disclosed in company proxy statements.
Insider at
Insider transactions
0 buys (P)
2 sells (S)
Net:
$-2,456,839
+ 95 non-open-market transactions below
last 12 months, based on the transactions shown below
Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted
95 other filings hidden
| Date | Ticker | Code | Shares | Price | Value | Owned after | Δ own | A/D | vs now |
|---|---|---|---|---|---|---|---|---|---|
| May 11, 2026 | MKSI | S | 4,355 | $319.94 | $1,393,339 | 49,439 Direct | -8.10% | Disposed | -11.5% (price as of 2026-08-21) |
| Feb. 20, 2026 | MKSI | S | 4,254 | $250.00 | $1,063,500 | 53,794 Direct | -7.33% | Disposed | 13.3% (price as of 2026-08-21) |
| March 1, 2024 | MKSI | S | 7,411 | $122.89 | $910,738 | 42,999 Direct | -14.70% | Disposed | 130.4% (price as of 2026-08-21) |
| Aug. 7, 2023 | MKSI | S | 5,377 | $101.40 | $545,228 | 42,738 Direct | -11.18% | Disposed | 179.2% (price as of 2026-08-21) |
| Aug. 7, 2023 | MKSI | S | 6,186 | $101.08 | $625,281 | 48,115 Direct | -11.39% | Disposed | 180.1% (price as of 2026-08-21) |
Showing latest 100 of 129 transactions
P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding
Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.
Derivative holdings (Form 4 Table II)
Options, RSUs and convertible securities reported on Form 4 Table II.
| Date | Ticker | Security | Underlying | Exercise price | Expiration | Shares | A/D |
|---|---|---|---|---|---|---|---|
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (2,493) | — | — | 2,493 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (2,336) | — | — | 2,336 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (1,576) | — | — | 1,576 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (563) | — | — | 563 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (1,788) | — | — | 1,788 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (3,451) | — | — | 3,451 | Disposed |
| Feb. 17, 2026 | MKSI | Restricted Stock Unit | Common Stock (3,328) | — | — | 3,328 | Acquired |
| Feb. 8, 2026 | MKSI | Restricted Stock Unit | Common Stock (7,009) | — | — | 7,009 | Acquired |
| Oct. 31, 2025 | MKSI | Restricted Stock Unit | Common Stock (341) | — | — | 341 | Disposed |
| Oct. 31, 2025 | MKSI | Restricted Stock Unit | Common Stock (144) | — | — | 144 | Disposed |
| Oct. 31, 2025 | MKSI | Restricted Stock Unit | Common Stock (82) | — | — | 82 | Disposed |
| Oct. 31, 2025 | MKSI | Restricted Stock Unit | Common Stock (52) | — | — | 52 | Disposed |
| Oct. 31, 2025 | MKSI | Restricted Stock Unit | Common Stock (158) | — | — | 158 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (1,648) | — | — | 1,648 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (588) | — | — | 588 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (1,870) | — | — | 1,870 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (3,608) | — | — | 3,608 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (1,645) | — | — | 1,645 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (2,287) | — | — | 2,287 | Disposed |
| Feb. 18, 2025 | MKSI | Restricted Stock Unit | Common Stock (7,822) | — | — | 7,822 | Acquired |
| Feb. 10, 2025 | MKSI | Restricted Stock Unit | Common Stock (1,766) | — | — | 1,766 | Acquired |
| Feb. 15, 2024 | MKSI | Restricted Stock Unit | Common Stock (2,287) | — | — | 2,287 | Disposed |
| Feb. 15, 2024 | MKSI | Restricted Stock Unit | Common Stock (1,645) | — | — | 1,645 | Disposed |
| Feb. 15, 2024 | MKSI | Restricted Stock Unit | Common Stock (3,608) | — | — | 3,608 | Disposed |
| Feb. 15, 2024 | MKSI | Restricted Stock Unit | Common Stock (1,869) | — | — | 1,869 | Disposed |
| Feb. 15, 2024 | MKSI | Restricted Stock Unit | Common Stock (1,017) | — | — | 1,017 | Disposed |
| Feb. 15, 2024 | MKSI | Restricted Stock Unit | Common Stock (2,033) | — | — | 2,033 | Disposed |
| Feb. 15, 2024 | MKSI | Restricted Stock Unit | Common Stock (4,945) | — | — | 4,945 | Acquired |
| Feb. 5, 2024 | MKSI | Restricted Stock Unit | Common Stock (10,825) | — | — | 10,825 | Acquired |
| Feb. 15, 2023 | MKSI | Restricted Stock Unit | Common Stock (1,645) | — | — | 1,645 | Disposed |
| Feb. 15, 2023 | MKSI | Restricted Stock Unit | Common Stock (2,286) | — | — | 2,286 | Disposed |
| Feb. 15, 2023 | MKSI | Restricted Stock Unit | Common Stock (1,016) | — | — | 1,016 | Disposed |
| Feb. 15, 2023 | MKSI | Restricted Stock Unit | Common Stock (2,033) | — | — | 2,033 | Disposed |
| Feb. 15, 2023 | MKSI | Restricted Stock Unit | Common Stock (1,281) | — | — | 1,281 | Disposed |
| Feb. 15, 2023 | MKSI | Restricted Stock Unit | Common Stock (1,845) | — | — | 1,845 | Disposed |
| Feb. 15, 2023 | MKSI | Restricted Stock Unit | Common Stock (5,609) | — | — | 5,609 | Acquired |
| Feb. 8, 2023 | MKSI | Restricted Stock Unit | Common Stock (6,860) | — | — | 6,860 | Acquired |
| Oct. 28, 2022 | MKSI | Restricted Stock Unit | Common Stock (2,179) | — | — | 2,179 | Disposed |
| April 29, 2022 | MKSI | Restricted Stock Unit | Common Stock (4,935) | — | — | 4,935 | Acquired |
| Feb. 15, 2022 | MKSI | Restricted Stock Unit | Common Stock (1,016) | — | — | 1,016 | Disposed |
| Feb. 15, 2022 | MKSI | Restricted Stock Unit | Common Stock (2,032) | — | — | 2,032 | Disposed |
| Feb. 15, 2022 | MKSI | Restricted Stock Unit | Common Stock (1,281) | — | — | 1,281 | Disposed |
| Feb. 15, 2022 | MKSI | Restricted Stock Unit | Common Stock (1,844) | — | — | 1,844 | Disposed |
| Feb. 15, 2022 | MKSI | Restricted Stock Unit | Common Stock (1,574) | — | — | 1,574 | Disposed |
| Feb. 15, 2022 | MKSI | Restricted Stock Unit | Common Stock (1,291) | — | — | 1,291 | Disposed |
| Jan. 21, 2022 | MKSI | Restricted Stock Unit | Common Stock (6,098) | — | — | 6,098 | Acquired |
| Oct. 28, 2021 | MKSI | Restricted Stock Unit | Common Stock (2,179) | — | — | 2,179 | Disposed |
| Feb. 16, 2021 | MKSI | Restricted Stock Unit | Common Stock (1,280) | — | — | 1,280 | Disposed |
| Feb. 16, 2021 | MKSI | Restricted Stock Unit | Common Stock (1,844) | — | — | 1,844 | Disposed |
| Feb. 16, 2021 | MKSI | Restricted Stock Unit | Common Stock (1,574) | — | — | 1,574 | Disposed |
| Feb. 16, 2021 | MKSI | Restricted Stock Unit | Common Stock (1,291) | — | — | 1,291 | Disposed |
| Feb. 16, 2021 | MKSI | Restricted Stock Unit | Common Stock (1,050) | — | — | 1,050 | Disposed |
| Feb. 16, 2021 | MKSI | Restricted Stock Unit | Common Stock (1,071) | — | — | 1,071 | Disposed |
| Feb. 16, 2021 | MKSI | Restricted Stock Unit | Common Stock (3,049) | — | — | 3,049 | Acquired |
| Jan. 25, 2021 | MKSI | Restricted Stock Unit | Common Stock (5,533) | — | — | 5,533 | Acquired |
| Feb. 18, 2020 | MKSI | Restricted Stock Unit | Common Stock (1,574) | — | — | 1,574 | Disposed |
| Feb. 18, 2020 | MKSI | Restricted Stock Unit | Common Stock (1,291) | — | — | 1,291 | Disposed |
| Feb. 18, 2020 | MKSI | Restricted Stock Unit | Common Stock (1,050) | — | — | 1,050 | Disposed |
| Feb. 18, 2020 | MKSI | Restricted Stock Unit | Common Stock (1,071) | — | — | 1,071 | Disposed |
| Feb. 18, 2020 | MKSI | Restricted Stock Unit | Common Stock (1,293) | — | — | 1,293 | Disposed |
| Feb. 18, 2020 | MKSI | Restricted Stock Unit | Common Stock (1,565) | — | — | 1,565 | Disposed |
| Feb. 18, 2020 | MKSI | Restricted Stock Unit | Common Stock (3,842) | — | — | 3,842 | Acquired |
| Jan. 27, 2020 | MKSI | Restricted Stock Unit | Common Stock (3,872) | — | — | 3,872 | Acquired |
| Oct. 28, 2019 | MKSI | Restricted Stock Unit | Common Stock (4,358) | — | — | 4,358 | Acquired |
Exercise/conversion price is blank when not applicable (e.g. RSUs).
Initial ownership (Form 3) 4 holdings
Securities held when first becoming an insider, per SEC Form 3.
| Date | Ticker | Security | Shares | Ownership |
|---|---|---|---|---|
| May 9, 2019 | MKSI | Common Stock | 38,986 | Direct |
| May 9, 2019 | MKSI | Restricted Stock Unit→ Common Stock (2,858) | 2,858 | Direct |
| May 9, 2019 | MKSI | Restricted Stock Unit→ Common Stock (4,243) | 4,243 | Direct |
| May 9, 2019 | MKSI | Restricted Stock Unit→ Common Stock (4,723) | 4,723 | Direct |
Compensation (DEF 14A)
Matched by name from proxy statements (DEF 14A) — verify against the filing.
MKSI
General Counsel| Fiscal year | Salary | Bonus | Stock awards | Option awards | Non-equity incentive | Pension change | Other | Total |
|---|---|---|---|---|---|---|---|---|
| 2024 | $510,148 | — | — | — | $107,131 | — | $36,264 | $1,932,454 |
| 2023 | $504,000 | — | — | — | $303,408 | — | $35,288 | $1,948,963 |
| 2022 | $499,773 | — | — | — | $349,809 | — | $32,725 | $1,990,429 |
Figures from the Summary Compensation Table of the company's proxy statement (DEF 14A). Compensation is not a recommendation.