NEW YORK, June 23, 2026, 18:04 (EDT)
- The Philadelphia Semiconductor Index slid 7.9%, dropping about 5.5 times as much as the S&P 500, which lost 1.44%.
- Micron, Sandisk, and Western Digital slid more than Nvidia, with signs of weakness in memory chips ahead of Micron’s earnings on Wednesday.
- KOSPI in South Korea dropped 9.99% as shares of Samsung Electronics and SK Hynix both slid over 12%.
U.S. chip stocks tumbled Tuesday, with the sharper move in memory stocks rather than just in Nvidia. The Philadelphia Semiconductor Index slid 7.9%. The Nasdaq lost 2.21% and the S&P 500 dropped 1.44%. Chips fell about 3.5 times harder than the Nasdaq, and about 5.5 times the S&P 500.
Micron Technology slid 13%, Sandisk was down 14% and Western Digital dropped 8.5%. All three fell harder than Nvidia, which lost 4.1%. AMD, Intel and Marvell dropped between 5.8% and 9.4%. Nvidia’s slide took its market cap under $5 trillion. The steepest selling hit memory and storage stocks, seen as direct AI server bets.
That’s important since memory chips have become a tight bet in the AI run. High-bandwidth memory, or HBM, is a kind of fast memory that AI processors need to crunch data. When investors doubt AI spending, stocks most linked to HBM supply tend to swing harder than Nvidia itself.
Roundhill Memory ETF dropped about 12% in recent trading, after hitting a record high Monday, Investopedia said. SK Hynix and Samsung make up 44% of the fund, with Micron pushing that total to nearly three-quarters. The fund had $23.4 billion in assets as of Monday. It reached $10 billion in just 43 days.
South Korea’s KOSPI finished down 9.99%, the biggest drop in over three months as Samsung Electronics and SK Hynix each fell more than 12%, triggering a 20-minute trading halt across the market. Samsung and SK Hynix now account for more than half the KOSPI’s market value, according to Reuters.
“Volatility has blown out,” said Alexander Redman, chief equity strategist at CLSA. He said “retailers are in the driving seat,” and flagged margin use and leveraged single-stock ETFs as a risk for Korea’s rally. Reuters
Pressure shifted to New York next. The Washington Post said the Nasdaq fell 2.4% at the open and the S&P 500 dropped 1.6%, following a near 4% slide in Japan’s Nikkei and almost 2% off Hong Kong’s Hang Seng.
The trade is getting “highly concentrated and flow-driven,” Ross Mayfield, investment strategy analyst at Baird, said, making it “vulnerable” to small changes in sentiment. Thomas Martin at Globalt said new headlines around AI “raises questions about all the spending” going to capacity and capital expenditure. Reuters
Micron is up next. The chipmaker will report fiscal Q3 results June 24 after the bell, set for 4:30 p.m. EDT. Its analyst call follows at 6 p.m. EDT. Micron’s guidance matters to more than just its own shares since the company is embedded in the memory pricing chain.
Micron shares extended losses after the company said Tuesday it had struck a strategic deal with Anthropic on memory and storage architecture, supply, AI adoption, and a new investment in Anthropic’s Series H. “AI has permanently elevated the role of memory,” said Sumit Sadana, chief business officer at Micron. Anthropic co-founder Tom Brown called memory and storage “central” to serving Claude. Micron Technology
Tuesday’s selling could just be traders crowding out of the same bets, not a real hit to demand. Micron might still talk up tight HBM supply and strong AI orders, and if inflation data is softer, that could cool off rate hike fears. But the risk if Micron says memory prices are topping and tighter Fed policy sticks around is sharper. The same funds and indexes that drove AI names higher could keep pulling money from the supply chain. LSEG data, cited by Reuters, shows traders now see higher odds of a second Fed hike by December. PCE inflation numbers land Thursday.
