A Deep Reinforcement Learning Approach for Portfolio Management in Non Short-selling Market

Reinforcement Learning (RL) has been applied to financial portfolio management in recent years. Current studies mostly focus on profit accumulation without much consideration of risk. Some risk-return balanced studies extract features from price and volume data only, which is highly correlated and missing representation of risk features. To tackle these problems, we propose a Weight Control Unit (WCU) to effectively manage position of portfolio management in different market statuses. A loss penalty term is also designed in the reward function to prevent sharp drawdown during trading. Moreover, Stock Spatial Interrelation (SSI) representing the correlation between two different stocks is captured by Graph Convolution Network (GCN) based on fundamental data. Temporal Interrelation is also captured by Temporal Convolutional Network (TCN) based on new factors designed with price and volume data. Both spatial and temporal interrelation work for better feature extraction from historical data, also make the model more interpretable. Finally, a Deep Deterministic Policy Gradient (DDPG) actor-critic RL is applied to explore optimal policy in portfolio management. We conduct our approach in a challenging non-short-selling market, experiment results show that our method outperforms the state-of-the-art methods in both profit and risk criteria. Specifically with 6.72% improvement on Annualized Rate of Return (ARR), 7.72% decrease in Maximum DrawDown (MDD) and a better Annualized Sharpe Ratio (ASR) of 0.112. Also, the loss penalty and WCU provide new aspects for future work in risk control.