Heavy foreign selling drives a 960-point slide
The TAIEX fell 960.65 points, or 1.95%, to close at 48,341.31 on Tuesday, October 13, with turnover running to NT$1.13 trillion (roughly US$35.2 billion). The pullback followed the index’s recent approach to the 50,000 threshold and tracked steep weakness across regional chip markets, where Korean memory names slid after executive cautions on AI supply-chain capital spending. Monday’s US session offered little support: the Philadelphia Semiconductor Index dropped 2.67%, the Nasdaq eased 0.44%, and the S&P 500 slipped 0.06%, even as the Dow gained 0.38%.
TSMC finished Tuesday at NT$2,490, with investors in wait-and-see mode ahead of the company’s Q3 investor conference this Thursday, October 15. Hon Hai closed at NT$240, MediaTek at NT$4,525 and UMC at NT$141.50. (A gap in our price feed for Monday’s session means we are not publishing daily changes for individual large caps today.)
One wrinkle worth flagging: against the 1.95% headline decline, the exchange’s official sector indices showed the Semiconductor sub-index up 2.27%, Shipping up 1.42% and Financials & Insurance up 1.13% on the day. That divergence between the capitalization-weighted headline index and the sector prints suggests the damage was concentrated rather than uniform — a breadth picture we will revisit once full constituent data settles.
Institutional flows: foreigners sell NT$165.34 billion
The exchange’s official net trading figures for October 13:
| Investor type | Net value | Direction |
|---|---|---|
| Foreign investors | NT$-165.34B | Net SELL |
| Investment trusts | NT$+23.87B | Net buy |
| Dealers (prop + hedge) | NT$-56.98B | Net sell |
| Three institutions combined | NT$-198.45B | Net SELL |
The aggregate figures indicate substantial net risk reduction by foreign institutions. Domestic investment trusts leaned against the move with NT$23.87 billion of buying, but it was a fraction of the foreign outflow. The currency offered little extra signal: USD/TWD traded near 32 on Tuesday.
Leverage and shorts: retail adds longs, institutions short Hon Hai
Taiwan’s three leverage channels told three different stories as of Monday’s session (Tuesday’s data is not yet published):
- Margin purchases (retail leveraged longs): the market-wide margin loan balance rose NT$6.92 billion to NT$653.3 billion. At the stock level, retail added leveraged longs in TSMC (+956 lots to 32,542) and Hon Hai (+460 lots to 61,708), while trimming UMC (-3,011 lots). Retail leverage building into weakness is a stress point if the decline extends.
- SBL balances (the institutional short channel): balances rose in 453 shortable issues and fell in 405 — mildly skewed toward short building. The standout was Hon Hai, where the SBL balance jumped 9.21 million shares to 61.14 million. That build coincides with the newly launched USITC Section 337 investigation into vertical power-delivery components for AI servers, which puts Taiwan’s server assemblers in the regulatory spotlight. UMC saw institutional shorts covered (-1.57 million shares).
- Retail margin shorts: small declines across the big caps — nothing notable.
Derivatives backdrop (previous session)
Heading into Tuesday — these are Monday’s figures, as TAIFEX publishes with a lag — foreign investors held a net short of 82,806 contracts in TAIEX futures open interest, and the options put/call volume ratio stood at 102.35%, modestly tilted toward puts. That was the defensive posture in place before Tuesday’s cash-market selling; Tuesday’s own positioning data arrives with the next release and will show whether the futures short was extended.
ADR gap and valuations
TSMC’s ADR closed Monday in New York at $444.35, about 14.7% above Tuesday’s Taipei close on an adjusted basis. That sits at the low end of the structural 15–25% premium the ADRs have carried in recent years — and the two closes come from different sessions, so the level itself is not a signal. The day-to-day change in the gap after Thursday’s earnings is what merits attention.
Valuation markers as of Monday’s close: TSMC trades at 29.4x earnings and 10.2x book with foreign ownership at 69.1% of shares outstanding; MediaTek at 76.4x earnings; Hon Hai at a comparatively modest 16.1x with a 2.93% yield. With US 10-year yields hovering near 5.24% and WTI crude above $93, the multiple on the AI complex remains the market’s sensitivity point.
What to watch
- TSMC’s Q3 investor conference, Thursday October 15 — capex and AI-demand commentary, set against the regional capex caution that triggered this week’s chip selloff, and the post-earnings move in the ADR premium.
- Follow-through on foreign selling — whether Tuesday’s NT$165.34 billion cash outflow extends, and whether the next TAIFEX release shows the futures net short deepening from -82,806 contracts.
- Hon Hai’s institutional short build — the 9.21-million-share SBL jump alongside the USITC Section 337 investigation into AI-server power components bears monitoring for both the stock and the assembler complex.
Disclaimer: This is an information and analysis publication, not investment advice. See our Methodology for data sources, standards, and our corrections policy.