Definition. The Glassnode Skew Index is a single measure of option market asymmetry. Unlike the conventional 25-delta skew, which samples two fixed points on the curve, it integrates option prices across broader sections of the surface to better capture shifts in sentiment between bullish and bearish positioning.

Technical. Implied volatility is split into two components: Up Variance from out-of-the-money calls and Down Variance from out-of-the-money puts, both computed by integrating option prices across strikes and time-weighting to fixed tenors. The Skew Index is the difference between the two.

Interpretation. Positive values indicate higher upside-focused implied volatility, often seen when markets price outsized upside tails or call demand. Negative values indicate higher downside-focused implied volatility, typical when downside hedging is dominant.

Notes. For further details, see Measuring Market Asymmetry: The Glassnode Skew Index.