Definition. IBIT Call-Put Delta Skew (Delta 25) is the model-interpolated implied-volatility skew between 25-delta calls and 25-delta puts for the IBIT ETF, reported by tenor. Each datapoint is the difference between call IV and put IV at target delta 25.

Technical. Values are projected onto standard tenors from the interpolated IV surface. The skew is unnormalized and expressed directly in IV points as call minus put.