Definition. Call-Put Delta Skew (Delta 20) is the model-interpolated implied-volatility skew between 20-delta calls and 20-delta puts, reported by tenor. Each datapoint is the difference between call IV and put IV at target delta 20 for the selected asset, exchange, and quote currency.

Technical. Values are taken from a single interpolated IV surface across delta and maturity, then projected onto standard tenors. The skew is unnormalized and expressed directly in IV points as call minus put.

This is the Point-in-Time (PiT) variant of Call-Put 20 Delta Skew. PiT metrics are strictly append-only and their history is immutable. The historic data does not necessarily reflect the best current knowledge, but the information at the time when a data point was first computed. PiT metrics are ideal candidates for applications in model backtesting and related quantitative purposes. Read our article on PiT metrics for more information.