Kathleen Flaherty Burke is VP & Secretary at MKS INSTRUMENTS INC (MKSI). They have made 5 open-market trades across 1 company since 2019, most recently 2026-05-11.
CIK 0001775435
Unrated. We grade insiders only on stock they chose to buy on the open market. Grants, option exercises and vesting say nothing about timing, so they don't count — which is why someone can file often and still have no grade. It isn't a bad sign: unrated buys beat every graded tier below A.
0 open-market purchases, against 5 sales. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| MKSI | 49,439 | $10.6M |
Shares reported on the most recent Form 4, priced at the 2026-05-12 close.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| MKSI | SELL | 2026-05-11 | 2026-05-12 | $319.94 | $1.4M | +1.2% | +8.9% | -7.7% |
| MKSI | SELL | 2026-02-20 | 2026-02-23 | $250.00 | $1.1M | -9.6% | -4.4% | +31.0% |
| MKSI | SELL | 2024-03-01 | 2024-03-04 | $122.89 | $1.8M | -1.9% | +6.1% | +0.9% |
| MKSI | SELL | 2023-08-07 | 2023-08-08 | $101.23 | $2.3M | -7.0% | -5.5% | -31.3% |
| MKSI | SELL | 2019-10-30 | 2019-10-31 | $110.55 | $2.3M | +1.3% | -2.4% | +1.2% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.