Skew

In equity options markets, the pattern that out-of-the-money put options are priced higher than equivalent OTM call options. Reflects investor demand for downside protection (hedging) and the asymmetric tail risk of stocks (crashes are sharper than rallies).

Skew steepens in stress, flattens in complacency. The S&P 500 skew index (SKEW) is published by Cboe and watched as a tail-risk gauge.