The CFO's massive open-market sales without a 10b5-1 plan are a strong bearish signal. Monitor for upcoming earnings or material corporate developments that may have prompted this selling. The VP's smaller sale adds to the cluster but is secondary in magnitude.
Price Chart
Executive Summary
UMC's CFO and SVP Liu Chitung sold 1.6 million shares worth $228.8M in two open-market transactions on September 16-17, 2026, and a Vice President sold an additional 10,000 shares worth $1.63M on September 22. This is a massive cluster of open-market selling by the company's top financial officer, representing a highly material percentage of market cap and a strong bearish signal.
Key Financial Metrics
Key Facts
- CFO & SVP Liu Chitung sold 1.6M shares for $228.8M in two open-market transactions (Sept 16-17, 2026).
- VP LIN JEN-TSUNG sold 10K shares for $1.63M on Sept 22, 2026.
- Total cluster value: $230.43M in open-market sales.
- No 10b5-1 plan indicated for any of the sales.
Financial Impact
Total insider sales of $230.43M, with CFO alone selling $228.8M. This is a highly material amount relative to UMC's market cap (likely >2% of market cap, though exact market cap not provided).
Risk Factors
- Potential undisclosed negative corporate developments (earnings miss, guidance cut, operational issues).
- Further insider selling could follow, exacerbating downward pressure.
Investment Themes
Documents Analyzed
This report is based on 1 SEC document filed with EDGAR.
| Document | Accession Number |
|---|---|
| CLUSTER Data (Synthetic) | cluster-UMC-1790071950155 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 23, 2026 4d ago | 6-K | $18.89 | awaiting T+5 | — | $19.45 (+2.96%) |
Oct 13, 2026 14d ago | 6-K | $22.39 $19.67 | ▼ −12.15% | ▼ −11.00% | $19.45 (−13.13%) |
Oct 7, 2026 20d ago | Court Ruling | $22.82 $20.92 | ▼ −8.33% | ▼ −8.05% | $19.45 (−14.77%) |
Oct 6, 2026 21d ago | 6-K | $23.19 $22.39 | ▼ −3.45% | ▼ −3.31% | $19.45 (−16.13%) |
Oct 5, 2026 22d ago | 6-K | $23.92 $22.55 | ▲ +5.73% | ▲ +6.15% | $19.45 (+18.69%) |
Sep 29, 2026 28d ago | 6-K | $24.72 $23.19 | ▼ −6.19% | ▼ −8.14% | $19.45 (−21.32%) |
Sep 22, 2026 5w ago | Insider Cluster | $25.77 $24.72 | ▲ +4.07% | ▲ +2.89% | $19.45 (+24.52%) |
Sep 4, 2026 7w ago | 6-K | $20.77 $21.90 | ▲ +5.44% | ▲ +6.65% | $19.45 (−6.36%) |
Sep 2, 2026 7w ago | 6-K | $19.97 $22.12 | ▲ +10.77% | ▲ +11.72% | $19.45 (−2.60%) |
Aug 26, 2026 8w ago | 6-K | $19.03 $19.97 | ▼ −4.94% | ▼ −5.06% | $19.45 (−2.21%) |
US Market Status
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