GCTS · Insider Trading
GCT Semiconductor Holding, Inc.
Every open-market purchase and sale reported by GCTS officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-10-02 | Robert Barker | Director | A | +12,971 | — |
| 2026-10-02 | Kukjin Chun | Director | A | +12,971 | — |
| 2026-10-02 | Hyunsoo Shin | Director | A | +12,971 | — |
| 2026-10-02 | Nelson Chan | Director | A | +12,971 | — |
| 2026-10-02 | Kyeongho Lee | Director | A | +12,971 | — |
| 2026-10-02 | Jeffrey Tuder | Director | A | +12,971 | — |
| 2026-09-14 | Jeong-Min Kim | Chief Technology Officer | A | +100,000 | — |
| 2026-09-14 | Edmond Cheng | Chief Financial Officer | A | +145,000 | — |
| 2026-09-14 | John Schlaefer | President, CEO & Class III Dir | A | +150,000 | — |
| 2026-09-14 | Alex Sum | Sr. VP of Sales and Marketing | A | +75,000 | — |
| 2026-07-07 | Jeffrey Tuder | Director | A | +9,259 | — |
| 2026-07-02 | Kukjin Chun | Director | A | +9,259 | — |
| 2026-07-02 | Robert Barker | Director | A | +9,259 | — |
| 2026-07-02 | Hyunsoo Shin | Director | A | +9,259 | — |
| 2026-07-02 | Kyeongho Lee | Director | A | +9,259 | — |
| 2026-07-02 | Nelson Chan | Director | A | +9,259 | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| Kyeongho Lee | Director | 1,109,093 | $1.61M |
| Hyunsoo Shin | Director | 827,039 | $1.20M |
| Jeong-Min Kim | Chief Technology Officer | 402,701 | $583.92K |
| John Schlaefer | President, CEO & Class III Dir | 352,728 | $511.46K |
| Edmond Cheng | Chief Financial Officer | 296,000 | $429.20K |
| Alex Sum | Sr. VP of Sales and Marketing | 258,743 | $375.18K |
| Robert Barker | Director | 164,681 | $238.79K |
| Jeffrey Tuder | Director | 164,161 | $238.03K |
| Nelson Chan | Director | 147,872 | $214.41K |
| Kukjin Chun | Director | 111,607 | $161.83K |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the GCTS quote page; the site-wide leaderboard is on the insider transactions hub.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.