Time-Series Momentum: A Monte Carlo Approach

Abstract

In this article the authors develop a Monte Carlo backtesting procedure for risk premium strategies and employ it to study time-series momentum (TSM). Relying on time-series models, empirical residual distributions, and copulas, the authors address two key drawbacks of conventional backtesting procedures. They create 10,000 paths of different TSM strategies based on the S&P 500 and a cross-asset-class futures portfolio. The simulations reveal a probability distribution that shows that strategies that outperform buy-and-hold in sample using historical backtests may (1) exhibit tail risks and (2) underperform or outperform when out of sample. The results are robust to using different time-series models, time periods, asset classes, and risk measures. TOPICS:Statistical methods, simulations, big data/machine learning Key Findings • Historical backtests suffer from the problem that they contain few tail events which may be an important driver for the performance of risk premium strategies. • We develop a Monte-Carlo procedure that uses a combination of copulas, time series models and empirical residual distributions to overcome this problem. • Applied to time-series momentum, we find that this strategy may (1) exhibit tail risks (2) underperform or outperform in the long-run.