Taiwan’s benchmark returned from a four-day holiday weekend with plenty of pent-up energy and very little conviction about direction. The TAIEX closed Tuesday up 54.80 points, or 0.12%, at 46,096.23 — a modest finish that conceals an intraday swing of more than 900 points — on expanded turnover of NT$976.5 billion. The over-the-counter Taipei Exchange index fared worse, falling 0.65% to 379.20.
A violent round trip
The session opened strong, as expected after Friday’s US rally: the Philadelphia Semiconductor Index had jumped 2.82% and the S&P 500 added 0.70% in the previous US session, buoyed by AI demand optimism and AI startup Anthropic’s IPO filing. The TAIEX gapped up 169.77 points and surged more than 544 points to an intraday high of 46,585. Then profit-taking in high-priced and heavyweight tech names took over, dragging the index all the way to a low of 45,676 — negative territory — before a late-session rebound carried it back above the 46,000 threshold.
TSMC (2330) anchored that recovery. The stock touched NT$2,405 intraday and drew more than 6,000 lots of buy orders in the final matching session to close up 0.63% at NT$2,400, contributing roughly 118 points to the index. Market chatter around the stock centered on reports of potential CoWoS advanced-packaging price adjustments, alongside supply-chain risk disclosures from Anthropic that underscored TSMC’s critical position in the AI build-out.
Semiconductors: foundry steady, memory on fire
The TWSE semiconductor sub-index rose 0.46%, but the dispersion beneath it was stark. Hon Hai (2317) gained 1.02% to NT$247.50 on AI server demand support, while MediaTek (2454) fell 1.25% to NT$3,960 and UMC (2303) dropped 2.39% to NT$122.50. Delta Electronics (2308) took the heaviest hit among large caps, down 3.20% on short-term selling pressure. It came into the session as one of the more richly valued large caps — 49.65x earnings and 13.80x book as of the October 22 TWSE valuation data, versus TSMC at 27.65x/9.61x and Hon Hai at 16.15x/1.80x — though MediaTek, at 66.23x/15.09x, carried the higher multiple.
The day’s genuine momentum story was memory. Projections of a roughly 20% DDR4 supply-demand gap, plus anticipation of Q3 earnings calls from Macronix (2337) and Powertech, sent Nanya Technology (2408) up more than 6% — it spiked over 8% intraday to touch NT$449 — with Winbond (2344), Macronix, Powerchip (6770) and Elite Semiconductor (3006) all gaining alongside.
Elsewhere, Financials & Insurance rose 0.74% and Shipping edged up 0.13%.
Institutional flows: trusts carry the day
The three major institutional categories combined for a net buy of NT$3.14 billion on the main board — but the composition matters more than the headline.
| Investor category | Net trading value (Oct 27) | Direction |
|---|---|---|
| Foreign investors | NT$-8.10B | Net sell (2nd consecutive session) |
| Investment trusts | NT$+23.65B | Net buy |
| Dealers (prop + hedge) | NT$-12.40B | Net sell |
| Combined | NT$+3.14B | Net buy |
Domestic investment trusts did all the lifting, absorbing selling from both foreign investors and proprietary dealers. On the derivatives side, foreign investors’ TAIEX futures net open interest stood at -87,297 contracts as of the October 22 session — the most recent published figure, so it reflects positioning going into the holiday rather than today’s activity. Taken together with the second straight day of cash-market selling, the foreign posture entering this week was cautious, though Tuesday’s futures data (due after this writing) will tell us whether the intraday shakeout changed that.
One housekeeping note on the ADR gap: TSM’s US-listed ADRs closed Monday at $424.37, about 14.9% above the Taipei close on an adjusted basis. That sits squarely within the structural 15–25% premium the ADRs have carried in recent years — the two closes are also from different sessions — so there is no signal in the level today; we flag it only when the gap moves.
Currency: the NT dollar wobbled, then steadied
Foreign equity selling and a US Dollar Index rebound above 102 pressured the New Taiwan dollar early. The currency opened at 32.530 per US dollar and weakened past 32.6 to an intraday low of 32.604, with midday turnover of US$1.127 billion, before recovering — USD/TWD ended the day at 32.49, down 0.25%. The central bank, for its part, published a report citing Middle East tensions, Fed rate expectations and global AI/semiconductor sell-offs as drivers of second-half foreign capital outflows, a useful official acknowledgment of the flow pattern visible in the TWSE data.
The overnight setup is quiet: S&P 500 futures were down 0.11% at 7,706.25 as Taipei closed.
What to watch
- Today’s TAIFEX foreign positioning print. The last published figure (-87,297 contracts net open interest, Oct 22) predates the holiday; whether foreigners covered or added into Tuesday’s 900-point swing is the key unknown.
- A third session of foreign cash selling. Two consecutive days of net sales plus intraday NT dollar weakness past 32.6 would start to look like a trend rather than holiday-adjacent noise if it extends.
- Memory earnings calls. Macronix and Powertech Q3 calls are the near-term catalyst for the DDR4 supply-gap thesis that powered Nanya’s 6%+ move.
Disclaimer: This is an information and analysis publication, not investment advice. See our Methodology for data sources, standards, and our corrections policy.