Lee John Tseng-Chung
Director · Officer · MKSI, CGNX
As of 2026-09-16, Lee John Tseng-Chung has 94 Form 4 transactions on record across 2 companies — 49 in the trailing 12 months.
Everything this person has disclosed to the SEC on Form 4 — across every company they file for — reconstructed from the public record. A filing history, not a tip sheet.
Reconstructed holdings
- Direct $31.7M
- Indirect $0
| MKSI | direct | 134,776 sh | $31.7M |
Reconstructed from this person's own Form 4 filings — the total each filing reported owning afterward, priced at the close on the as-of date shown. A filed position can lag the real one.
Direct and indirect holdings (e.g. through a trust or fund) are tagged separately, as filed.
Trades by company
Filing ledger
| Date | Company | Action | Shares @ price | Value | Ownership Δ | Owned after | Filing |
|---|---|---|---|---|---|---|---|
| 2026-08-14 | MKSI | Sale | 10,000 @ $302.01 | $3.0M | −6.9% of holding | 134,776 | Form 4 |
| 2026-05-22 | MKSI | Sale | 10,000 @ $315.48 | $3.2M | −6.5% of holding | 144,696 | Form 4 |
| 2026-02-20 | MKSI | Sale | 13,310 @ $256.05 | $3.4M | −7.2% of holding | 171,386 | Form 4 |
| 2026-02-20 | MKSI | Sale | 12,812 @ $256.93 | $3.3M | −7.5% of holding | 158,574 | Form 4 |
| 2026-02-20 | MKSI | Sale | 1,988 @ $257.81 | $513K | −1.3% of holding | 156,586 | Form 4 |
| 2026-02-20 | MKSI | Sale | 1,890 @ $259.70 | $491K | −1.2% of holding | 154,696 | Form 4 |
88 award / exercise / gift records — not counted as purchases
| Date | Company | Action | Shares | Owned after | Filing |
|---|---|---|---|---|---|
| 2026-02-21 | CGNX | Option exercise | 2,913 | 0 | Form 4 |
| 2026-02-21 | CGNX | Option exercise | 2,913 | 24,820 | Form 4 |
| 2026-02-18 | CGNX | Option exercise | 8,324 | 21,907 | Form 4 |
| 2026-02-18 | CGNX | Option exercise | 8,324 | 0 | Form 4 |
| 2026-02-17 | MKSI | Withheld for tax | 32,548 | 184,696 | Form 4 |
| 2026-02-17 | CGNX | Award / grant | 4,817 | 4,817 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 7,654 | 177,097 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 22,088 | 169,443 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 12,091 | 84,828 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 16,989 | 96,919 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 7,208 | 113,909 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 3,859 | 121,117 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 7,654 | 124,976 | Form 4 |
| 2026-02-17 | MKSI | Award / grant | 15,593 | 154,717 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 22,088 | 132,629 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 12,091 | 84,828 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 16,989 | 96,919 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 7,208 | 113,909 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 3,859 | 121,117 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 7,654 | 124,976 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 22,088 | 132,629 | Form 4 |
| 2026-02-17 | MKSI | Award / grant | 15,593 | 154,717 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 12,091 | 217,244 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 16,989 | 205,153 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 7,208 | 188,164 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 3,859 | 180,956 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 3,859 | 180,956 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 7,654 | 177,097 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 22,088 | 169,443 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 12,091 | 217,244 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 16,989 | 205,153 | Form 4 |
| 2026-02-17 | MKSI | Option exercise | 7,208 | 188,164 | Form 4 |
| 2026-02-08 | MKSI | Award / grant | 50,972 | 139,124 | Form 4 |
| 2026-02-08 | MKSI | Award / grant | 50,972 | 139,124 | Form 4 |
| 2025-10-31 | MKSI | Withheld for tax | 2,003 | 147,270 | Form 4 |
| 2025-10-31 | MKSI | Option exercise | 1,651 | 88,153 | Form 4 |
| 2025-10-31 | MKSI | Option exercise | 352 | 89,804 | Form 4 |
| 2025-10-31 | MKSI | Option exercise | 352 | 147,622 | Form 4 |
| 2025-10-31 | MKSI | Option exercise | 1,651 | 149,273 | Form 4 |
| 2025-10-31 | MKSI | Option exercise | 352 | 89,804 | Form 4 |
Source: SEC Form 4 filings. Each row links to its original filing.
Research tool, not investment advice — historical frequencies, not recommendations. A product of Marovel Technologies LLC. Full terms.