According to Central News Agency (CNA), Taiwan's TAIEX fell 2,049.85 points (-4.49%) to 43,575.13 by 10:40 a.m. on July 17, 2026, with TSMC down more than 4%. Separately, cnyes reported the intraday drop exceeded 2,800 points, a historic record, as passive-component and substrate stocks fell in a domino effect.
How severe was the intraday plunge, and what record did it set?
According to CNA, the TAIEX fell 2,049.85 points to 43,575.13 as of 10:40 a.m. on July 17, 2026, a decline of 4.49%, with turnover of roughly NT$637.3 billion (E1). Separately, cnyes reported that the intraday point drop exceeded 2,800 points, which the outlet described as the largest intraday point decline in the index's history (E10).
How did the market open, and what technical signal appeared?
CNA reported that the TAIEX opened lower at 45,234.08 points and broke below its 5-day moving average during the early session, with the intraday decline exceeding 2,000 points (E7). This means the index had already lost ground before the open and continued falling through the morning without recovering the short-term trend line.
How did TSMC and AI-related tech leaders perform?
CNA reported that TSMC (台積電) fell NT$100 intraday to NT$2,370, a drop of more than 4% (E2). Overnight in the U.S., the PHLX Semiconductor Index (SOX, 費半) fell 4.29% and TSMC's American Depositary Receipts (ADR) declined 2.32%, while Taiwan stock index futures fell 976 points in after-hours trading, per CNA (E4).
Which heavyweight stocks hit limit-down, and which fell hardest?
CNA reported that UMC (聯電), Yageo (國巨), and Nan Ya Plastics (南亳) all hit limit-down during the session (E3). According to cnyes, Walsin Technology (華新科) suffered the steepest decline among the affected stocks, with its share price described as having "halved" (E12).
What chain reaction hit electronics, passive components, and substrate makers?
CNA reported that among the three major substrate makers, Nan Ya PCB (南電) and Unimicron (欣興) fell more than 8%, while Kinsus (景碩) and Zhen Ding (臻鼎) dropped more than 9%; memory-related names Winbond (華邦電) and Nanya Technology (南亞科) also saw their share prices dive (E6). CNA separately reported the electronics sub-index fell 4.48% (E8). cnyes reported that more than 10 passive component stocks hit limit-down in what it called a domino effect (E11).
How did financials and other indices perform, and did Asian markets fall in tandem?
CNA reported the financial sub-index fell 0.45%, a far smaller decline than the broader market, while the Taipei Exchange (TPEx, 櫃買) index fell more than 5% (E8). Regionally, CNA reported that Japan's stock market fell nearly 4% intraday and South Korea's market fell more than 6% (E5).
What does the drop in high-priced stocks reveal?
CNA reported that roughly 1,500 stocks fell during the session, and the number of stocks priced above NT$1,000 ("thousand-dollar club") retreated to 46 (E9).
| Metric | Value | Source |
|---|
| TAIEX intraday change (10:40 a.m.) | -2,049.85 pts / -4.49% to 43,575.13 | CNA (E1) |
| TAIEX historic intraday point drop | over 2,800 pts | cnyes (E10) |
| TAIEX opening level | 45,234.08 pts | CNA (E7) |
| TSMC intraday change | -NT$100 to NT$2,370 (>4%) | CNA (E2) |
| SOX (US) | -4.29% | CNA (E4) |
| TSMC ADR | -2.32% | CNA (E4) |
| Taiwan index futures (after-hours) | -976 pts | CNA (E4) |
| Japan stock market (intraday) | near -4% | CNA (E5) |
| South Korea stock market (intraday) | over -6% | CNA (E5) |
| Electronics sub-index | -4.48% | CNA (E8) |
| Financial sub-index | -0.45% | CNA (E8) |
| TPEx index | over -5% | CNA (E8) |
| Nan Ya PCB / Unimicron | over -8% | CNA (E6) |
| Kinsus / Zhen Ding | over -9% | CNA (E6) |
| Passive component stocks at limit-down | over 10 | cnyes (E11) |
| Stocks priced above NT$1,000 | retreated to 46 | CNA (E9) |
| Stocks declining intraday | about 1,500 | CNA (E9) |
What this means
The figures reported by CNA and cnyes show the sell-off was broad rather than isolated to one segment. TSMC's intraday decline in Taipei (over 4%, E2) was steeper than its ADR's overnight fall in the U.S. (2.32%, E4), while the SOX's 4.29% drop (E4) was closer in magnitude to TSMC's Taipei-session decline than to its ADR move — suggesting the domestic session added to losses already visible overseas. Supply-chain-adjacent sectors were hit harder than TSMC itself: substrate makers Kinsus and Zhen Ding fell over 9% and passive component stocks saw more than 10 names hit limit-down (E6, E11), compared with TSMC's roughly 4% drop (E2). Regionally, CNA's figures show Taiwan's electronics-heavy decline (TAIEX -4.49%, E1) sat between Japan's near-4% intraday fall and South Korea's over-6% decline (E5), while the financial sub-index's comparatively mild 0.45% loss (E8) contrasted with the TPEx's over-5% drop (E8), pointing to a sell-off concentrated in tech and electronics rather than financials. The retreat of NT$1,000-plus stocks to just 46, alongside roughly 1,500 declining names (E9), reflects how widely the pressure spread across the board.