UMC · Insider Trading
United Microelectronic Corp.
Every open-market purchase and sale reported by UMC 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 |
|---|---|---|---|---|---|
| 2026-09-22 | Jen-Tsung Lin | Vice President | Sell | −10,000 | −$1.63M |
| 2026-09-17 | Chitung Liu | CFO & SVP | Sell | −1,600,000 | −$228.80M |
| 2026-09-08 | Chitung Liu | CFO & SVP | J | — | — |
| 2026-07-13 | Chitung Liu | CFO & SVP | Sell | −1,900,000 | −$294.29M |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| Chitung Liu | CFO & SVP | 2,789,757 | $55.29M |
| Jen-Tsung Lin | Vice President | 1,172,140 | $23.23M |
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 UMC 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.