Deep Reinforcement Trading with Predictable Returns

Abstract: Classical portfolio optimization often requires forecasting asset returns and their corresponding variances in spite of the low signal-to-noise ratio provided in the financial markets. Modern deep reinforcement learning (DRL) offers a framework for optimizing sequential trader decisions but lacks theoretical guarantees of convergence. On the other hand, the performances on real financial trading problems are strongly affected by the goodness of the signal used to predict returns. To disentangle the effects coming from return unpredictability from those coming from algorithm un-trainability, we investigate the performance of model-free DRL traders in a market environment with different known mean-reverting factors driving the dynamics. When the framework admits an exact dynamic programming solution, we can assess the limits and capabilities of different value-based algorithms to retrieve meaningful trading signals in a data-driven manner. We consider DRL agents that leverage classical strategies to increase their performances and we show that this approach guarantees flexibility, outperforming the benchmark strategy when the price dynamics is misspecified and some original assumptions on the market environment are violated with the presence of extreme events and volatility clustering.