Tuesday in Taipei was a session of two halves. A ferocious open, powered by Monday’s 4.29% surge in the Philadelphia Semiconductor Index and a 1.49% gain in the S&P 500, lifted the TAIEX as much as 882.69 points to a fresh all-time high of 48,601.53. Then the tape turned. Profit-taking and pre-holiday risk-reduction ground the gain down to 81.33 points, leaving the index at 47,800.17, up 0.17% — still a record closing high, but well shy of the 48,000 line, on heavy turnover of NT$1.02 trillion. Breadth told the honest story: decliners beat advancers 652 to 343, with 127 unchanged.
Institutional flows: foreigners buy NT$44.7 billion
The flow data leaned firmly against the fading price action. All three institutional groups were net buyers on Tuesday:
- Foreign investors: net BUY of NT$44.73 billion
- Investment trusts: net buy of NT$0.24 billion
- Dealers (proprietary + hedge): net buy of NT$15.85 billion
- Combined: net buy of NT$60.82 billion
The currency confirmed the inflow. The Taiwan dollar appreciated alongside the equity buying, with USD/TWD easing 0.41% to 31.68 at Tuesday’s close.
Single stocks: TSMC drags, the ASIC complex sprints
TSMC (2330) was the day’s defining drag. It surged to an intraday high of NT$2,510 — briefly restoring a market capitalization above NT$65 trillion — before sellers took over, and it closed down 0.81% at NT$2,460. With the index heavyweight fading, the TWSE Semiconductor sub-index finished nearly flat at +0.08% despite the spectacular US lead-in.
The rotation went instead to IC design and AI hardware. MediaTek (2454) rose 3.39% to NT$5,180, off an intraday high of NT$5,480, on Googlebook chip-supply and edge-AI catalysts. Hon Hai (2317) added 1.20% to NT$253 and UMC (2303) gained 1.91% to NT$160. The speculative heat was in the ASIC and substrate complex: Global Unichip (3443) jumped 9.98% to a record NT$8,375, substrate makers Unimicron, Nan Ya PCB and Kinsus all hit their 10% limits, liquid-cooling supplier Kaori (8996) locked limit-up at NT$1,655, and ASPEED (5274) closed limit-up at NT$21,800 — the first stock in Taiwan market history above the NT$20,000 mark. On the other side, profit-taking hit optoelectronics and equipment names hard: Epileds fell 9.93%, Fittech 9.15% and Polytronics 8.30%. Financials & Insurance (+0.67%) quietly outperformed; Shipping was flat at +0.04%.
| Stock | Close (NT$) | Day | PER | Foreign ownership |
|---|---|---|---|---|
| TSMC (2330) | 2,460.00 | -0.81% | 28.75 | 69.22% |
| MediaTek (2454) | 5,180.00 | +3.39% | 82.74 | 56.43% |
| Hon Hai (2317) | 253.00 | +1.20% | 16.48 | 40.37% |
| UMC (2303) | 160.00 | +1.91% | 23.61 | 41.32% |
Valuations and ownership as of Monday’s TWSE data (Sept 21).
Positioning: cash buying against a still-short futures book
A caveat up front: TAIFEX data run a day behind, so the latest derivatives readings describe Monday’s positioning, not Tuesday’s — they cannot explain today’s intraday fade. As of Monday’s session, foreign investors held a net short of 74,081 contracts in TAIEX futures (having bought a modest 2,034 contracts net on the day), and the options put/call volume ratio stood at 125.10%. That hedged or defensive futures book, set against Tuesday’s NT$44.7 billion of foreign cash buying, is the tension worth tracking when today’s TAIFEX figures publish.
Taiwan’s three leverage channels — worth keeping separate — showed no alarm as of Monday’s data. Retail leveraged longs (margin purchases) grew: the market-wide margin loan balance rose NT$9.0 billion to NT$603.0 billion, with Hon Hai margin balance up 653 lots and Delta Electronics up 488, while TSMC margin was essentially flat. In the institutional short channel (SBL, distinct from retail margin shorts), breadth was balanced — balances rose in 453 issues and fell in 435. Stock-level moves were modest: UMC’s SBL balance added 1.44 million shares, while Hon Hai saw 1.65 million shares of SBL covering; TSMC’s SBL balance was little changed.
ADR gap check
TSMC’s ADR closed at $445.14 in Monday’s US session, about 14.6% above Tuesday’s Taipei close on a per-share basis. Remember the frame: the ADR premium is structural — roughly 15–25% in recent years, reflecting limited fungibility — and the two closes come from different sessions. At 14.6% the gap sits at the low end of its recent range; it is the day-to-day change in this spread that carries signal, not the level, and nothing here suggests mispricing.
What to watch
- Today’s TAIFEX release: whether foreign investors trimmed the 74,081-contract net futures short after another day of heavy cash buying — convergence or continued hedging near record highs.
- Breadth around 48,000: Tuesday’s 652-to-343 negative breadth at a record close is the kind of narrowness that either resolves with rotation broadening out or with the leaders catching down.
- The overnight lead: S&P 500 futures are flat at 7,836.25 (+0.04%) — a quiet setup after Monday’s US surge, putting the burden of proof back on local flows.
Disclaimer: This is an information and analysis publication, not investment advice. See our Methodology for data sources, standards, and our corrections policy.