Semiconductor Equipment Stocks Plummet... $1.8 Billion Market Cap Vanishes in a Day

MKS Inc. (NASDAQ: MKSI), a semiconductor equipment supplier trading on the Nasdaq, plunged 5.29% on the 26th to close at $388.61.

Trading volume topped 1.53 million shares, and the company’s market capitalization stands at about $26.2 billion (roughly KRW 35 trillion). In a single day, it lost approximately $1.3 billion—around KRW 1.8 trillion—in market value.

That same day, New York markets weakened on broad selling pressure in semiconductor and tech stocks amid growing concerns of an overheated AI investment environment, dragging down MKS and its peers.

Earlier this month, buoyed by strong AI-driven demand, MKS beat market expectations for its Q1 2026 results and raised its outlook for Q2. Nevertheless, the stock has remained volatile since the earnings release and is now undergoing a further correction.

MKS is a U.S. technology company that supplies instrumentation, process-control equipment, and specialty chemicals used in semiconductor wafer fabrication, printed circuit boards, and advanced packaging. After shareholder approval at its 2025 annual meeting, the company officially changed its name to MKS Inc.

While recent major acquisitions have raised expectations for increased investment in semiconductors and electronic packaging, investors are also monitoring the company’s elevated debt levels and performance risks tied to industry cyclicality.