ARM Surges 277% YTD on AI Chip Optimism, Trading at Record Valuation

ARM Holdings (ARM-US) surged 277% year-to-date in 2026, becoming one of the best performers in the S&P 500, according to Bloomberg, driven by investor optimism over its expansion into AI chip design. The stock rallied 97% from its May 15 low following a Federal Trade Commission antitrust probe, increasing the company's market value by approximately $218 billion.

The semiconductor designer now trades at 175 times forward earnings, compared to 51 times at the start of the year, with a price-to-sales ratio reaching 68 times—both among the highest in the S&P 500. Analysts note the valuation already reflects growth expectations through 2030, as CEO Rene Haas targets $15 billion in AI chip revenue by that year.