Semiconductor stocks suffered one of their worst single-session declines of 2026 on Wednesday, erasing more than a trillion dollars in market value across the sector as investors locked in gains after a relentless first-half run that had produced triple-digit returns for many of the industry's biggest names. Micron Technology and Sandisk each fell more than 10.6%, AMD lost 6.9%, and Intel dropped 9%, while Nvidia and Broadcom shed between 1% and 2%. The VanEck Semiconductor ETF lost 5.4% on the day.
The selloff's proximate trigger was a combination of factors analysts said had been building for weeks. Micron shares had climbed roughly 260% year-to-date before Wednesday's decline, with Sandisk posting an even more extraordinary advance of more than 750%, leaving both names deeply extended on a valuation basis even accounting for the structural growth story in AI memory demand. With the broader AI infrastructure narrative entering a period of reassessment — investor attention had begun shifting from hardware acceleration to whether AI spending was translating into discernible revenue and earnings returns across the ecosystem — the sector was ripe for a correction.
A secondary pressure point came from the jobs and rates backdrop. Wednesday's soft ADP employment report of 98,000 private-sector jobs, while technically below estimates, was insufficient to roll back Federal Reserve rate hike expectations materially, leaving the rate environment hostile to high-multiple growth stocks. The 10-year Treasury yield held near 4.48% heading into Thursday's nonfarm payrolls release, maintaining pressure on discount rates applied to forward earnings estimates.
The contagion spread rapidly to Asian markets overnight. South Korea's Kospi fell 7.89%, its largest single-day decline in months, with SK Hynix losing more than 12% and Samsung Electronics shedding over 8%. The Korean Exchange temporarily halted trading for five minutes at the open to contain volatility. Japan's Nikkei 225 fell 2.47%, while Kioxia, one of the world's largest flash memory producers, dropped roughly 10%.
Despite the severity of the session, several strategists cautioned against interpreting the move as a structural reversal of the AI semiconductor investment case. Ned Davis Research strategist Rob Anderson wrote that the rotation out of semiconductors was 'healthy' and consistent with the broader bull market's characteristic of passing market leadership from one sector to another. 'A passing of the baton to a non-commodity cyclical sector would be further evidence that the stock market is entering the second half of the year in a position of strength,' Anderson said, noting that the bull market's fourth year has repeatedly featured this type of rotation.
BofA analysts noted that a bubble risk indicator for technology and semiconductor stocks has been rising, urging investors to be selective rather than buy indiscriminately. Micron specifically faces a near-term test: the CHIPS Act clock means that restrictions on certain uses of Micron's cash expire on December 9, 2026, two years after the company signed its definitive CHIPS Act agreements, a trigger BofA models could unlock $31.7 billion in buybacks for fiscal 2027 alone.
For Thursday's session, the semiconductor sector's direction will be heavily influenced by the June nonfarm payrolls report due at 8:30 AM. A strong jobs number reinforcing rate-hike expectations could extend the selloff, while a softer read might spark a relief bounce in oversold chip names heading into the Independence Day holiday weekend.