TAIPEI (Taiwan News) — Stocks in Taiwan Semiconductor Manufacturing Co. (TSMC) and other chip manufacturers have taken a dive following political developments in the U.S.

On Thursday (July 18), TSMC stocks fell to NT$988 (US$30.31) per share, a decrease of NT$42, slashing its market value by more than NT$1 trillion, per CNA. TSMC is scheduled to hold its second quarter briefing on Thursday afternoon, which will be attended by Chairperson C.C. Wei (魏哲家).

On Wednesday, more than NT$16.3 trillion (US$500 billion) in stock value was wiped off Wall Street’s semiconductor index, per Reuters. Stocks in Nvidia, Qualcomm, and ASML Holding also lost value, while companies with U.S. chip manufacturing operations, including GlobalFoundries and Intel, saw increases.

The changes come after Republican Party presidential nominee Donald Trump said on Wednesday he thought Taiwan should pay the U.S. for defense. In the same interview he repeated claims Taiwan had taken U.S. chip business.

Taiwan produces over 90% of the world’s most advanced semiconductors, and over 60% of the world's total supply. 

The U.S. is required to provide Taiwan with the means to defend itself under the Taiwan Relations Act, and in April it provided US$2 billion in military financing for Taiwan and other allies in the Asia Pacific region.

A report published by Bloomberg on Tuesday added concerns about chip stocks. The report cited sources who said the U.S. is considering using “the most severe trade restrictions available” against China if U.S. firms continue to provide the country with access to advanced semiconductor technology.

Existing U.S. trade restrictions have already cut into many of the world’s largest technology firms’ trade with China. Nvidia's revenue from China was about 18% of its total revenue in the quarter ended April 28, compared with 66% in the same period the year before.