AI Semiconductor Stocks Plummet... 3 Trillion Won in Equipment Stocks Vanished in a Day

Onto Innovation Inc. (NASDAQ: ONTO) plunged 13.76% on July 1, closing at $303 in New York trading. Some 1.09 million shares changed hands, wiping out roughly $1.8 billion—nearly KRW 3 trillion—in market value in a single day. Prior to the drop, the company’s market capitalization stood at about $15 billion (approximately KRW 23 trillion).

Although Onto Innovation made no adverse announcements, it appears to have been caught up in a wave of profit-taking across high-valuation AI and semiconductor stocks after the Nasdaq Composite fell 0.6% on semiconductor sector worries. At the end of June, the company updated its investor presentation, reaffirming its growth story centered on AI-focused packaging inspection equipment. Nevertheless, short-term valuation adjustment risks have come into sharper relief.

Formed in 2019 by the merger of Rudolph Technologies and Nanometrics, Onto Innovation is a U.S. provider of semiconductor process control and metrology equipment. Through its wafer and advanced packaging inspection systems, the company is well positioned to benefit from AI and high-bandwidth memory (HBM) investments by leading global foundries and memory manufacturers. Having emphasized the growth potential of new products—such as the Dragonfly G5 platform for AI packaging—in its Q1 2026 results and guidance released in May, Onto now sees its financial performance and order momentum reemerging as key drivers of valuation following this latest share-price decline.