Taiwan’s TAIEX ended Thursday, September 10, in the red, closing at 46,940.49, down 0.51% (a fall of 242.87 points) on turnover of about NT$713.97 billion (roughly US$22.69 billion). The index opened lower near 47,131 and probed an intraday low of 46,573 before trimming losses into the 13:30 close. The defining story sat on the flow side: foreign investors turned net sellers, snapping a four-session buying run, while the heavyweight semiconductor complex offered only a mixed cushion.
Institutional flows: foreigners lead the exit
The three major institutional groups sold a combined NT$50.31 billion at Thursday’s close — this site’s signature gauge, and unambiguously negative on the day.
| Group | Net trading value (Sep 10) | Direction |
|---|---|---|
| Foreign investors | NT$-38.33B | Net SELL |
| Investment trusts | NT$+1.79B | Net BUY |
| Dealers (prop + hedge) | NT$-13.76B | Net SELL |
| Three institutions | NT$-50.31B | Net SELL |
Foreign investors did the heavy lifting on the sell side at NT$38.33 billion, breaking a recent stretch of net buying. Dealers (proprietary plus hedge) added NT$13.76 billion of selling. Domestic investment trusts were the lone net buyer at a modest NT$1.79 billion — an imperfect but familiar partial offset when overseas money steps back.
TSMC: record August revenue, softer shares
TSMC (2330) eased NT$15, or 0.61%, to NT$2,450, weighing on the benchmark despite constructive fundamentals. With Thursday marking the monthly revenue filing deadline for Taiwan-listed companies, TSMC reported August consolidated revenue of NT$514.81 billion — a single-month record, up about 10.1% month-on-month and 53.3% year-on-year, underpinned by advanced-node AI accelerator demand. The muted share reaction was a reminder that a strong print can still meet sell-the-news profit-taking after a strong run.
MediaTek bucks the tape; Apple chain retreats
MediaTek (2454) was the standout, climbing NT$95, or 2.05%, to NT$4,720. UMC (2303) added 0.71% to NT$142.50. The offset came from Apple-aligned names: Hon Hai (2317) slipped NT$1 to NT$251 (-0.40%), while optical supplier Largan also eased, as the group faced post-launch profit-taking. Among TWSE sector indices, Semiconductor rose 0.26% and Financials & Insurance 0.34%, while Shipping led at +1.81%.
Leverage and short channels
Taiwan runs three distinct channels — keep them separate. Margin purchases (rong-zi) are retail leveraged longs: the market-wide margin loan balance stood at NT$587.2 billion as of the previous session (Sep 9), up a marginal NT$0.90 billion, so retail leverage barely budged. The institutional short channel — securities borrowing and lending (SBL) — showed balances rising in 512 issues and falling in 357 as of Sep 9, a modest breadth tilt toward more borrowing rather than an outright short surge. Stock-level detail (previous-session data):
- UMC (2303): retail margin longs jumped +15,491 lots (to 200,072) while its SBL balance fell 1.87M shares — retail adding longs even as the institutional short trimmed.
- TSMC (2330): margin +402 lots; SBL -58,000 shares.
- Hon Hai (2317): margin -77 lots; SBL +19,000 shares.
- MediaTek (2454): margin +127 lots; SBL -497,099 shares.
The positioning scoreboard (foreign cash-market sell NT$-38.33B, margin balance +NT$0.90B, SBL breadth up 512 / down 357) summarizes the sections above and is cited here for context only, not as fresh data.
Valuations and foreign ownership
Valuation metrics as of the Sep 9 close; foreign ownership per TWSE.
| Stock | Close (Sep 10) | PER | PBR | Yield | Foreign own. |
|---|---|---|---|---|---|
| TSMC (2330) | 2,450 | 28.57 | 9.94 | 0.89% | 69.29% |
| Hon Hai (2317) | 251 | 16.61 | 1.85 | 2.85% | 40.46% |
| MediaTek (2454) | 4,720 | 76.38 | 17.40 | 1.16% | 55.96% |
| UMC (2303) | 142.50 | 21.28 | 4.00 | 1.84% | 41.18% |
| Delta Elec. (2308) | — | 57.13 | 15.88 | 0.65% | 61.93% |
ADR and currency
The New Taiwan dollar was little changed at 31.52 per US dollar (+0.05%). On the ADR gap, TSM closed at US$435.36 in New York on Sep 9, about 12% above Thursday’s Taipei close on a share-equivalent basis (1 ADR = 5 shares). That premium is structural — historically in the 15-25% range — and compares two different sessions, so the level is not an arbitrage signal; if anything the ~12% reading sits at or below the low end of the usual band, and only day-to-day changes in the gap carry information. In the prior US session the Philadelphia Semiconductor Index rose 0.37% to 11,931.32 even as the S&P 500 slipped 0.48% to 7,636.36; S&P 500 futures pointed modestly higher overnight at 7,663 (+0.25%).
What to watch
- Foreign follow-through. Thursday’s NT$38.33 billion of foreign selling broke a four-session buying run — whether Friday extends the exit or reverts will set the near-term tone.
- TAIFEX final settlement, Sep 16. Third-Wednesday futures/options settlement is four trading sessions out; expect positioning noise to build into it.
- TSMC record revenue vs. price. A single-month sales record met a lower share — watch whether the AI demand narrative reasserts or profit-taking persists across the chip complex.
This briefing is informational and not investment advice.
Disclaimer: This is an information and analysis publication, not investment advice. See our Methodology for data sources, standards, and our corrections policy.