A rally that didn’t hold
The TAIEX closed Tuesday at 47,105.78, down 220.49 points or 0.47%, after one of the wider intraday ranges in recent weeks — a swing of more than 550 points. The index surged over 250 points at the open to touch 47,578 before profit-taking in the large tech holdings erased the gains through the session. Turnover was NT$876.66 billion. Electronics fell 0.70% and did the damage; the defensive rotation was visible in financials and insurance (+1.20%) and food stocks (+1.19%), with shipping also firm at +0.93%.
The setup offered little external direction. US markets were closed Monday for Labor Day, so the freshest Wall Street reference remained Friday’s session — a strong one for chips, with the Philadelphia Semiconductor Index up 3.37% even as the S&P 500 eased 0.38%. Taipei’s morning pop looked like a delayed echo of that SOX move; it met sellers almost immediately. S&P 500 futures drifted 0.21% lower during Asian hours, reinforcing the caution ahead of this week’s US CPI and PPI prints.
Semis: TSMC holds the line, everything around it sags
TSMC (2330) was the index’s main support, adding NT$10 (+0.41%) to close at NT$2,470 after touching NT$2,505 intraday, with late-session institutional rebalancing of 6,163 lots trimming the advance. The company also announced a joint initiative with ASML to move the industry toward 12-inch EUV lithography photomasks, aimed at fab efficiency and lower manufacturing costs.
The rest of the complex was heavy. Hon Hai (2317) fell 1.76% to NT$251.50, MediaTek (2454) lost 1.05% to NT$4,710, and UMC (2303) was the notable casualty among the big caps, down 4.20% to NT$137.00. The AI hardware chain saw sharper cuts further down: Quanta (2382) slid 5.61% to NT$328 and server-rail maker King Slide (2059) dropped 9.96% to NT$12,520, while ASPEED (5274) held flat at NT$19,220. Memory was the bright spot — Winbond rose 4.44% and Nanya Technology 2.71% on price recovery and tight capacity. The TWSE semiconductor sub-index still eked out +0.21%, flattered by TSMC’s weight.
Flows: a genuinely split tape
Official TWSE data for Tuesday shows the three institutional groups pulling in different directions:
- Foreign investors: net BUY NT$13.27 billion — the only buyers among the three.
- Investment trusts: net SELL NT$4.72 billion.
- Dealers (proprietary + hedge): net SELL NT$18.54 billion.
- Combined: net SELL NT$9.99 billion.
Foreign money buying into a down tape while dealers sell aggressively is a more constructive configuration than the headline decline suggests. The currency corroborates the inflow story: USD/TWD was quoted around 31.5 on September 8, the Taiwan dollar firming through the session in a tight 31.45–31.47 intraday band.
Leverage and the short channels (Monday’s data)
Positioning data lags a day, so the following is Monday’s (Sep 7) picture. Market-wide margin purchase balances — retail leveraged longs — rose NT$6.38 billion to NT$588.3 billion. In the institutional short channel, SBL balances rose in 586 shortable issues and fell in 285, a breadth reading that leans toward building institutional shorts even as the retail long book grows.
UMC is where the channels diverge most sharply, and Monday’s positioning foreshadowed Tuesday’s 4.2% drop: retail margin longs jumped 8,743 lots to 178,956 and retail margin shorts rose 2,370 lots — a crowded retail battleground — while institutional SBL shorts actually eased 104,000 shares to 58.9 million. Elsewhere the tone was calmer: Hon Hai saw SBL shorts cut by 860,000 shares alongside a 483-lot margin-long reduction, and TSMC’s margin longs fell 864 lots with SBL essentially flat.
Where valuations stand
| Stock | PER | PBR | Yield | Foreign ownership |
|---|---|---|---|---|
| TSMC (2330) | 28.52 | 9.92 | 0.89% | 69.27% |
| MediaTek (2454) | 78.61 | 17.91 | 1.12% | 56.0% |
| UMC (2303) | 21.50 | 4.04 | 1.83% | 41.59% |
| Hon Hai (2317) | 16.88 | 1.88 | 2.80% | 40.55% |
| Delta (2308) | 58.88 | 16.36 | 0.63% | 61.92% |
Valuations as of Monday’s close, TWSE.
One housekeeping note on the ADR: TSM closed at $428.91 in New York on Friday, roughly 9.4% above Tuesday’s Taipei close on a per-share basis. That gap compares closes from different sessions and the ADR habitually trades at a structural premium (roughly 15–25% in recent years), so the level itself signals nothing — but it is worth tracking whether the gap widens once US trading resumes after the holiday, given Friday’s outsized SOX move.
What to watch
- Thursday, Sep 10 — monthly revenue filings. Taiwan-listed companies, TSMC included, must report August sales by the deadline. The single most important data point of the week for the AI supply chain names that sold off today.
- US CPI and PPI. With Monday’s US holiday behind us, inflation prints will reset the global rate backdrop that Taipei has been trading around blind.
- Foreign flow persistence and the UMC retail book. Whether Tuesday’s NT$13.27 billion foreign buy extends — and whether UMC’s swollen margin-long balance starts to unwind after the 4.2% drop — will shape the tape into week’s end.
Disclaimer: This is an information and analysis publication, not investment advice. See our Methodology for data sources, standards, and our corrections policy.