TAIPEI, Jan 8, 2026, 13:53 (GMT+8)
- A Taiwan lawmaker said the Taiex benchmark is being distorted by TSMC’s heavy weighting.
- Margin debt hit NT$351 billion, the highest level since June 2008, data compiled by Bloomberg showed.
- A Smartkarma analysis flagged December earnings revisions and an estimated 2026 earnings-per-share level for an MS-Taiwan index.
Taiwan’s stock rally drew political heat this week after a senior opposition lawmaker said the Taiex benchmark no longer reflects the broader market because it is dominated by Taiwan Semiconductor Manufacturing Co, which he said accounts for more than 40% of total market value. “The market structure has lost its balance,” Kuomintang legislator Lin Te-fu said. 1 . 6
The warning lands at an awkward moment for investors: the index has pushed into new territory above 30,000 points on an AI-driven run, and money is moving quickly into a narrow slice of chip-linked names. In a market where many funds, brokers and retail traders benchmark performance to the Taiex, concentration changes the risk math.
Margin debt — loans investors use to buy shares — rose to NT$351 billion ($11.1 billion) on Monday, a 17-year high and the biggest since June 2008, Bloomberg-compiled data showed. 2 . 7
A Smartkarma quantitative analysis said its MS-Taiwan earnings-revision gauge rose 7% in December, from 1,179 to 1,262, and it estimated 2026E EPS — forecast earnings per share for 2026 — at 70.49 at month-end. The note highlighted revisions across sectors, including Caliway Biopharmaceuticals, Nan Ya Plastics, China Development Financial, MediaTek, TSMC and China Steel. 3 . 8
The Taiex surged 2.57% on Monday to 30,105.04 as TSMC jumped 5.36% to a record NT$1,670, contributing about 680 points to the index’s gain, and breadth was thin: 749 main-board stocks fell that day. TSMC later hit NT$1,705 on Tuesday as the Taiex ended at 30,576.3, before profit taking pushed TSMC down 1.76% on Wednesday and pulled the index lower by 0.46%, Focus Taiwan reported. 4 .
Hua Nan Securities analyst Kevin Su said buyers had been betting that TSMC will keep benefiting from demand for its most advanced processes after its 2-nanometer process started mass production during the AI boom. PGIM said optimism has also been tied to expectations of strong fourth-quarter earnings and another round of capital spending on advanced manufacturing, while non-tech shares “largely traded in weakness,” Su said. Turnover hit NT$765.807 billion on Monday, with domestic funds and proprietary traders net buyers while foreign investors were net sellers, the Taipei Times reported. 5 .
But the rally rests on a narrow base. If chip earnings disappoint, or if investors decide the AI trade has run too far, heavy leverage can turn a normal pullback into forced selling that ripples well beyond the biggest names.
Financial Supervisory Commission Chairman Peng Jin-long said the regulator is prepared for market uncertainty and has told the Taiwan Stock Exchange and the Taipei Exchange to promote companies with sound fundamentals to draw investor attention and improve trading liquidity, according to Focus Taiwan.
