Lee John Tseng-Chung

Director, President & CEO, President & COO, Sr. VP & COO · SEC CIK 1414656
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Buy track record

How this insider's open-market purchases have performed
This insider has no open-market purchases in the records we parsed, so there's no buy track record to score. Their full filing history is below.
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Open-market buys
$0
0 trades
Open-market sells
$13.63M
9 trades
Net flow
−$13.63M
Net selling
Total filings
45
transactions shown

Full transaction history

All Form 4 activity across every company, newest first
View on SEC EDGAR ↗
MKSI
Sell Lee John Tseng-Chung · Director, President & CEO · Open-market sale · filed 2w ago ΔOwn −6.5%

Lee John Tseng-chung sold $3.15M of MKSI, trimming their stake 6%.

−$3.15M
10,000 sh @ $315
MKSI
Sell Lee John Tseng-Chung · Director, President & CEO · Open-market sale · filed Feb 23, 2026 ΔOwn −7.2%

Lee John Tseng-chung sold $3.41M of MKSI, trimming their stake 7%.

−$3.41M
13,310 sh @ $256
MKSI
Sell Lee John Tseng-Chung · Director, President & CEO · Open-market sale · filed Feb 23, 2026 ΔOwn −7.5%

Lee John Tseng-chung sold $3.29M of MKSI, trimming their stake 7%.

−$3.29M
12,812 sh @ $257
MKSI
Sell Lee John Tseng-Chung · Director, President & CEO · Open-market sale · filed Feb 23, 2026 ΔOwn −1.3%

Lee John Tseng-chung sold $512.5K of MKSI, trimming their stake 1%.

−$512.5K
1,988 sh @ $258
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MKSI
Sell Lee John Tseng-Chung · Director, President & CEO · Open-market sale · filed Feb 23, 2026 ΔOwn −1.2%

Lee John Tseng-chung sold $490.8K of MKSI, trimming their stake 1%.

−$490.8K
1,890 sh @ $260
MKSI
Option exercise Lee John Tseng-Chung · Director, President & CEO · Option exercise · filed Feb 18, 2026 ΔOwn +5.9%
+$0
12,091 sh
MKSI
Tax withholding Lee John Tseng-Chung · Director, President & CEO · Tax withholding · filed Feb 18, 2026 ΔOwn −15%
−$8.49M
32,548 sh @ $261
MKSI
Option exercise Lee John Tseng-Chung · Director, President & CEO · Option exercise · filed Nov 4, 2025 ΔOwn +1.1%
+$0
1,651 sh
MKSI
Tax withholding Lee John Tseng-Chung · Director, President & CEO · Tax withholding · filed Nov 4, 2025 ΔOwn −1.3%
−$287.9K
2,003 sh @ $144

Frequently asked questions

How is Lee John Tseng-Chung's win rate calculated?

We take every open-market purchase (SEC code P) we can match to a stock price, then compare the split- and dividend-adjusted price on the purchase date to the most recent close. The win rate is the share of those buys currently trading above the purchase price. Sales and share grants are not scored.

Why are some buys not included in the score?

A purchase is excluded if we can't price it — for example if the ticker is missing from the filing, the company has been delisted, or the security isn't a common stock we can match to market data. Excluded counts are shown next to the scored total.

What do the 1M / 3M / 6M / 12M columns mean?

They show each purchase's return after a fixed holding period — one, three, six, and twelve months from the buy date — using split- and dividend-adjusted prices. This separates good entry timing from simply holding a long-running winner. A dash means that horizon hasn't elapsed yet for that trade, or the stock couldn't be priced at that date.

Does a high win rate mean I should copy this insider?

No. Past performance does not predict future results, sample sizes are often small, and an insider's edge in their own company doesn't transfer to yours. This is context, not a recommendation. InsiderSource is not investment advice.

Where does this data come from?

Trades come from Lee John Tseng-Chung's SEC Form 4 filings on EDGAR. Prices come from public market data and are split/dividend-adjusted. Always verify against the original filings before acting.