Stochastic Fill Models

Algorithm

Stochastic Fill Models represent a class of algorithms primarily employed in options pricing and cryptocurrency derivatives markets to simulate order book dynamics and assess the impact of large trades. These models move beyond traditional stochastic volatility frameworks by incorporating a discrete-time representation of order flow, allowing for a more granular analysis of market microstructure effects. The core innovation lies in modeling the incremental fills—the small, discrete quantities of an asset acquired or divested—as stochastic processes, often driven by latent variables reflecting hidden order book states. Consequently, they provide a framework for evaluating the price impact of trades, particularly relevant in illiquid crypto markets where slippage can significantly affect profitability.