We study the SABR stochastic volatility model with the volatility-of-volatility parameter ν . We provide a method to expand the price C_SABR(S, K, ν, σ, τ ) of a European call in this model as a Taylor series in ν , C_SABR(S, K, ν, σ, τ ) = C_BS(S,K, σ, τ ) ν C₁ ν²C₂ . . . ν^kC_k O(ν<sup>k...

We identify a feedback loop between fire sales and equity option returns. The demand effect of fire sales induced by mutual fund extreme outflows decreases delta-hedged put option returns by 4-10% per year and increases the expensiveness by 2.5%. We address endogenous concerns using instrumental...