Taiwan’s TAIEX added 0.25% to a fresh all-time high of 48,475.74 on Friday, its third straight gain, as money rotated into optical communication, PCB and petrochemical names while TSMC, MediaTek and Hon Hai all closed lower. All three institutional camps were net buyers, led by investment trusts at NT$4.91 billion.
The TAIEX finished at an all-time closing high of 48,353.49 (+0.86%) on Thursday, closing at the session top on NT$837.4 billion turnover. Foreign investors bought a net NT$21.94 billion, UMC jumped 4.53%, and passive components saw a wall of limit-ups.
By the time TSMC’s quarterly investor conference begins, the quarter’s revenue is already public — Taiwan requires monthly sales filings by the 10th. What actually moves the stock: gross-margin guidance, capex plans, 3nm/2nm node mix, AI platform share, and the day-to-day change in the TSM ADR’s structural 15-25% premium over Taipei.
Taiwan’s benchmark rose 0.65% to 47,940.13 on the final day of September, sealing a 3.93% monthly gain at all-time highs. Foreign investors net bought NT$29.64 billion, glass-substrate and silicon-wafer names went limit-up, and the TWD held near 31.85 after testing 31.9.
Returning from the Mid-Autumn Festival break, Taipei played catch-up with a weak Wall Street session: the TAIEX fell 392.64 points to 47,631.96, foreign investors sold a net NT$63.2 billion, and MediaTek lost 7.1% on reports of adjusted Google order allocations. Petrochemicals and shipping bucked the tide.
Taiwan’s benchmark set an all-time intraday high of 48,601 before heavy profit-taking pared the gain to 0.17%. Foreign investors still bought NT$44.73 billion of cash equities, while TSMC dragged and the ASIC and substrate complex ran to limit-up.
On ex-dividend day, Taiwan exchanges cut a stock’s reference price by the full cash payout; 填息 (tianxi, ‘filling the gap’) means climbing back to the pre-ex price. How the July–September season works, why a smaller gap needs a smaller move to fill, and how the 21% withholding tax changes the math for foreign holders.
Taipei absorbed Monday’s 5.9% Philadelphia Semiconductor rout with a comparatively contained 0.77% decline to 45,511.49, as TSMC held green ahead of its ex-dividend date. Foreign investors net sold NT$62.7B, part of a combined NT$79.1B institutional outflow, with TAIFEX settlement and the CBC meeting looming.
Taiwan stocks fell 0.70% Monday as calls to slow frontier AI development, hawkish Fed repricing ahead of the FOMC and Middle East tensions overwhelmed a strong Friday close on Wall Street. Foreign investors sold a net NT$36.96 billion while defensive money rotated into financials.
Taiwan’s benchmark gave back an early 250-point rally to close at 47,105.78 on Tuesday. TSMC held green at NT$2,470, but Hon Hai, MediaTek and UMC dragged electronics lower. Foreign investors bought NT$13.27B net while dealers sold NT$18.54B — a split tape ahead of Thursday’s monthly revenue filings.