Control Variates
Control variates is a variance reduction technique that utilizes the known analytical solution of a simpler, related financial instrument to refine the estimate of a more complex derivative. By calculating the difference between the simulated price and the theoretical price of the control instrument, the model can adjust the simulation result for the complex instrument.
This adjustment effectively removes the noise associated with the simulation process. For example, if pricing an exotic cryptocurrency option, one might use a standard European option on the same underlying asset as the control variate.
Because the two instruments share similar risk factors, the error in the simulation of the control instrument is highly correlated with the error in the complex instrument. This method provides a powerful way to reduce computational load while maintaining high precision in pricing.