Why is Taiwan Semiconductor Manufacturing stock plunging today?

Taiwan Semiconductor Manufacturing ADR fell 9.8% in morning trading to reach $357.16, as a sweeping Democratic victory in the November 4 U.S. midterm elections sent shockwaves through the AI and semiconductor sector, with investors rapidly repricing the regulatory risk surrounding data center construction and AI infrastructure spending across the United States.

The primary catalyst was the Democratic Party’s capture of both chambers of Congress and key governorships in Texas and Georgia — two states that together account for roughly a third of all planned AI data center investment in the country. Analysts at Evercore ISI warned that "a more restrictive data center development environment could create incrementally more negative sentiment for AI infrastructure exposed names," while Wedbush’s Dan Ives called the Texas result the "biggest worry" for technology investors on election night. Since TSMC is the world’s dominant manufacturer of advanced chips powering AI data centers, any threat to the pace of that buildout flows directly to its order book and growth outlook. Adding to the pressure, investors are also growing cautious ahead of TSMC’s November 10 monthly sales report, which must clear a demanding $53.3 billion quarterly revenue hurdle to justify the stock’s elevated valuation. Bernstein’s same-day price target raise to $600, citing surging custom ASIC CPU demand from Amazon and Google, was unable to counteract the wave of institutional selling.

The selloff was broad and systemic across the semiconductor space, with Micron, AMD, and Nvidia all declining sharply alongside TSMC, confirming this was a sector-wide de-risking event rather than a company-specific issue. The Philadelphia Semiconductor Index had already plunged 3.1% on November 4 as the initial election results came in, setting a weak foundation for today’s extended losses. Technical selling pressure following a breakdown below key moving averages has further compounded the downside, as algorithmic and momentum-driven strategies amplified the move.

The broader market offered no refuge, with the S&P 500 sliding 3.3%, the Nasdaq tumbling 4.8%, and the Dow declining 2.2%, as growth and technology stocks bore the brunt of post-election repositioning. The combination of a hostile new political landscape for AI infrastructure, institutional de-risking, technical deterioration, and an upcoming revenue test has converged to push TSMC’s ADR to $357.16 — well below its open of $378.96 and sitting closer to the day’s low of $352.45, now roughly 26.8% off its 52-week high of $487.47.