From Volatility to Variance: A Skew-Enhanced SABR Model and Its Empirical Study in the Chinese Financial Options Market

Battle Count: 78

Highly relevant for quantitative trading in options markets. The skew-SABR model provides a practical, computationally tractable tool for fitting implied volatility surfaces, which is essential for option pricing, hedging, and strategy development. The model's ability to capture asymmetric volatility structures (skew and higher-order asymmetry) is directly applicable to trading strategies that exploit mispricings in the volatility surface. The empirical validation on Chinese index and ETF options makes it immediately applicable to the growing Chinese derivatives market.

Moderate complexity. The model requires implementing the Hagan-SABR formula (well-documented) plus two additional linear terms (c·log(K/f) + d). Calibration involves a 5-parameter nonlinear least-squares optimization with a Gaussian weighting scheme. The stochastic process specification and derivation are mathematically involved, but the final formula is straightforward to implement. The main complexity lies in ensuring numerical stability during calibration and handling edge cases in the asymptotic approximation.

The paper provides detailed mathematical derivations, explicit formulas for the skew-SABR model, calibration procedures, and comprehensive empirical tables. However, the market data is sourced from the International Digital Economy Academy (IDEA) database, which may not be publicly accessible. The methodology is fully described but requires proprietary data for exact replication.