The July 1–2, 2026 Semiconductor Selloff: A Complete Fact-Check of Causes, Impacts, and the Bubble Signal That Preceded It

The Philadelphia Semiconductor Index (SOX)

The SOX closed at 13,353.28, down 893.68 points, or -6.27% on July 1 . That was one of its largest single-day drops in over a year, compounding earlier selloffs in late June where the index had fallen 7.9% in a single session .

Hardest-Hit US Chip Stocks

Sources confirm the following approximate declines on July 1:

• KLA Corporation — down ~12%
• Micron (MU) — down over 10%
• Applied Materials — down ~10%
• Lam Research — down ~9.7%
• Intel (INTC) — down roughly 9%
• AMD — down approximately 6.9%
• Broadcom (AVGO) — down ~1.4% on July 1, but had been a trigger for a $1.3 trillion wipeout in early June after a guidance miss

Bank of America Bubble Risk Indicator

As of June 30, BofA's proprietary gauge stood at 0.91 for the PHLX Semiconductor Sector and 0.82 for the Technology Select Sector . The indicator measures return distribution across returns, volatility, momentum (skew), and convexity (kurtosis). A reading above 0.80 historically signals true bubble territory .

Spillover to Asian Markets (July 2)

Asian markets opened sharply lower on July 2, tracking the US tech rout:

• South Korea's KOSPI sank 5.1% to 7,877.45 .
• SK Hynix lost 7.7% .
• Samsung Electronics tumbled 6.4% .
• CNBC separately reported Samsung down over 7% and SK Hynix sinking over 9% at the open .

The Asia selloff was amplified because South Korea's market had become extraordinarily concentrated in chip stocks, with Samsung and SK Hynix together dominating the KOSPI's weighting during its AI-driven rally .

The Record Q2 Rally Context

The Philadelphia Semiconductor Index had rallied approximately 81% in Q2 2026, described as a "record-breaking" quarter . The index gained as much as 87.8% according to some estimates, before the late-June and early-July corrections . This meant that even after a 6.27% single-day drop, the SOX had merely given back a fraction of its extraordinary Q2 gains, leaving valuations still stretched .