Semiconductor stocks spent years as the market’s favorite children. Lately, they have been sent to their rooms.
The ratio of the Philadelphia Semiconductor Index (SOX) to the S&P 500 has fallen to 1.45. That is its lowest reading since April 2026 and a 24% drop from its mid-June peak.
A losing streak with a 2008 vintage
Since mid-June 2026, the SOX has dropped roughly 24%, while the S&P 500 has added about 2% over the same stretch.
The damage sped up recently. The SOX logged eight straight losing sessions, its longest skid since October 2008, during the depths of the financial crisis.
Over that streak, the index shed approximately 16%. It closed at 11,137.29 on October 16, 2026.
The selling was not selective. On October 16, all 30 stocks in the index finished lower.
Some of the biggest names took notable hits that day. Broadcom, Micron, AMD, Intel, Lam Research, and KLA each fell about 5%, while Arm dropped roughly 7%.
Add it up across semiconductor and AI-linked companies, and the slide has erased more than $1 trillion in market value.
Why investors are pulling back
Investors have grown uneasy about elevated borrowing at AI-focused cloud providers such as CoreWeave.
Unexpectedly hot US inflation has pushed financing costs higher, which makes debt-funded expansion more expensive.
Context: still far above the 2022 lows
Even after this slide, the SOX-to-S&P ratio remains up 142% from its 2022 bear-market low.
The S&P 500 has managed a modest gain while one of its most influential sectors has been in retreat.
What this means for investors
The first is spending: any guidance from cloud providers and hyperscalers on AI capital budgets will be scrutinized closely.
The second is credit. Balance sheets at debt-heavy AI infrastructure players like CoreWeave are likely to stay in focus, since stress there would ripple back to chip suppliers.
The third is inflation and rates. If price pressures keep running hot and financing stays expensive, the case for aggressive debt-funded buildouts gets weaker.
The last time the SOX lost this many sessions in a row, the backdrop was a global financial crisis. Today’s conditions are different, with a broader market that is still rising.
For now, the SOX-to-S&P ratio is the cleanest gauge to track. A continued slide would suggest investors are still repricing the AI buildout, while stabilization could indicate the selling has run its course.
Disclosure: This article was edited by Diego Almada Lopez. For more information on how we create and review content, see our Editorial Policy.