Volatility Regime-Dependent Portfolio Optimization: Empirical Analysis of Deep Reinforcement Learning Agents
摘要
Financial markets exhibit regime shifts characterized by low, medium, and high volatility, limiting the effectiveness of static portfolio strategies. This study evaluates five deep reinforcement learning (DRL) algorithms—A2C, PPO, DDPG, TD3, and SAC—applied to NIFTY50 constituents within a trading environment incorporating transaction costs, position limits, and turbulence-based risk penalties. Portfolio performance is examined across volatility regimes identified using rolling variance and DCC-GARCH conditional variance, and benchmarked against both the NIFTY50 index and a dynamic minimum-variance portfolio. The results show that DRL agents outperform the market benchmark during most medium- and low-volatility regimes, but their relative performance varies systematically across market conditions, with no single algorithm consistently dominant. During periods of heightened volatility, variance-based portfolios provide stronger downside protection. Overall, the findings highlight the importance of regime-aware and adaptive portfolio frameworks that combine learning-based strategies with risk-focused approaches.