Quantum Monte Carlo algorithm for solving Black-Scholes PDEs for high-dimensional option pricing in finance and its complexity analysis
Jianjun Chen, Yongming Li, Ariel Neufeld
TL;DR
This work addresses high-dimensional option pricing under the Black-Scholes model by introducing a quantum Monte Carlo algorithm that handles correlated assets and general CPWA payoffs. The method loads a discretized multivariate log-normal distribution and a CPWA payoff into rotated quantum form and uses a Modified IQAE subroutine to estimate the option price with provable error $|u-\tilde{U}|\le\varepsilon$ with probability $1-\alpha$. The authors prove polynomial-in-$d$ and $\varepsilon^{-1}$ scaling for qubit and gate resources, and they show a speed-up for bounded payoffs over classical Monte Carlo, along with detailed error analyses (truncation, quadrature, payoff loading, rotation, and QAE). Numerical experiments in 1D and 2D demonstrate the practicality of the approach and its extension to higher dimensions, supported by a Qiskit-based package $qfinance$. The results establish a rigorous foundation for quantum speed-ups in high-dimensional financial PDEs and provide a concrete path toward scalable quantum pricing in practice.
Abstract
In this paper we provide a quantum Monte Carlo algorithm to solve high-dimensional Black-Scholes PDEs with correlation for high-dimensional option pricing. The payoff function of the option is of general form and is only required to be continuous and piece-wise affine (CPWA), which covers most of the relevant payoff functions used in finance. We provide a rigorous error analysis and complexity analysis of our algorithm. In particular, we prove that the computational complexity of our algorithm is bounded polynomially in the space dimension $d$ of the PDE and the reciprocal of the prescribed accuracy $\varepsilon$. Moreover, we show that for payoff functions which are bounded, our algorithm indeed has a speed-up compared to classical Monte Carlo methods. Furthermore, we provide numerical simulations in one and two dimensions using our developed package within the Qiskit framework tailored to price CPWA options with respect to the Black-Scholes model, as well as discuss the potential extension of the numerical simulations to arbitrary space dimension.
