When US stocks sell off: what to check — VIX, the chip index, and expected earnings moves
A broad selloff can make US stock moves hard to put in context. Volatility, semiconductor stocks, and earnings expectations offer different views of the same session, without predicting what comes next.
VIX and the volatility curve
VIX measures near-term expected volatility derived from S&P 500 option prices; VIX3M measures expected volatility over a longer horizon. When VIX is above VIX3M, the volatility curve is inverted: options price more near-term volatility than longer-term volatility. Neither reading predicts the market’s direction.
Why the chip index can move more
The Philadelphia Semiconductor Index (SOX) concentrates on chipmakers and semiconductor equipment companies, while the Nasdaq includes a broader mix of businesses. Shared industry demand and concentrated exposures can make SOX move more than the broader Nasdaq, though that will not happen every session.
Earnings expectations and the actual reaction
During a selloff week, uncertainty about the market as well as a company’s report can raise option prices and the pre-report expected move; it does not always rise. In SIGNUM HQ, check the earnings expected move before the report, then compare it with the actual post-report close-to-close reaction in the earnings comparison or selloff briefing when available. The option range runs to expiry, while the actual reaction covers one regular session, so their horizons differ. The range is not a guarantee.
An example
On 2026-11-05, the S&P fell 4.36%, the Nasdaq fell 5.52%, and SOX fell 12.25%; VIX closed at 28.18. This was a semiconductor-led decline. These observations do not establish a cause or predict the next move.
iOS and Android. The same numbers explained here, live.
See this on a live ticker →