We introduce an out-of-sample neural-network-based measure of firm-level operating leverage, which outperforms existing ones in capturing the elasticity of operating profits to gross profits. Strikingly, our analysis uncovers a non-monotonic—and potentially negative—relationship between operating leverage and the risk premium. This challenges conventional wisdom and contradicts explanations that link operating leverage to the value premium. A production-based asset pricing model incorporating both variable and fixed costs provides a possible rationale for these empirical findings. Furthermore, our analysis offers a fresh perspective on the idiosyncratic volatility premium by emphasizing the interplay between the operating hedge effect induced by variable costs and the operating leverage effect induced by fixed costs.