A broad-based rout in semiconductor stocks erased more than $680 billion in market value Tuesday, with the Philadelphia Semiconductor Index suffering its worst session in months as traders braced for tighter monetary policy under incoming Federal Reserve Chair Kevin Warsh.
The Philadelphia Semiconductor Index tumbled 6.3% Tuesday, its steepest decline in over a year, as a coordinated selloff swept across memory, equipment and fabless chipmakers. The Nasdaq 100 dropped more than 2%, while the Nasdaq Composite fell 1.4% to trade near 25,677 — its 50-day moving average — after breaching that level for the first time since April.
"The market is repricing rate expectations aggressively, and semiconductors — the most crowded trade of 2026 — are bearing the brunt of the unwind," said Priya Mehta, equity market strategist. "When positioning is this concentrated on one side, even a modest catalyst can trigger outsized moves."
Memory chipmakers led the decline. Micron Technology fell 9% ahead of its earnings report due Wednesday after the close. SanDisk dropped 12%, Western Digital lost 11% and Seagate declined 13.2%. Lam Research fell 10.9%, Marvell Technology dropped 10.4% and Advanced Micro Devices lost 9.4%. Intel slid 8.4%, ASML fell 5.6% and TSMC dropped 4%. Nvidia, the sector's largest constituent by market capitalization, slipped 2.6%, pushing its market value below $5 trillion.
The selloff was concentrated in semiconductors while some mega-cap tech names stabilized. Microsoft gained more than 2% and Apple added 0.8% as bargain hunters rotated into names that had already corrected earlier this year. The divergence underscores a market sorting winners from losers within technology rather than selling the sector indiscriminately.
Expectations of tighter policy under Warsh added pressure. Rate-sensitive growth stocks were already vulnerable after last week's hawkish hold by the Federal Reserve, and the chip trade — which powered the Philadelphia Semiconductor Index to a 75% year-to-date gain through early June — took the brunt of the repricing. The index is now down nearly 5% from its early June peak.
The technical damage was significant. The Nasdaq Composite's breach of its 50-day moving average at 25,677 — a level that had held every test since April — opens the door to further downside. A sustained move below that level could target the swing bottom at 24,980, with a 50% to 61.8% retracement zone extending to 23,940 to 23,173. The 200-day moving average sits inside that zone.
Micron's earnings Wednesday will be the next test for the sector. If the company's results show AI-driven demand remains intact, Tuesday's selloff could draw dip buyers. If guidance disappoints, the selloff could deepen.
This article is for informational purposes only and does not constitute investment advice.