Smile Effect

The smile effect is a specific pattern in the implied volatility surface where out-of-the-money and in-the-money options have higher implied volatilities than at-the-money options. When plotted, this creates a U-shape or smile.

This occurs because the market assigns a higher probability to extreme price moves than would be predicted by a normal distribution. In crypto, this often reflects the market's expectation of sudden, large movements in either direction.

Traders use the smile to identify which options are relatively expensive and to hedge against tail risks. It is a critical aspect of the volatility surface that distinguishes real-world market pricing from theoretical models that assume constant volatility.