01. Backtesting & Optimization Refresher

AI For Trading C5 L4 A01 Refresher V2

Fundamentals of Backtesting a Trading Agent

A reinforcement learning trading agent must be evaluated under various market conditions to assess its profitability. Here’s a concise guide:

  • Market Context Matters: Financial markets are unstable, requiring tests in multiple contexts.

  • Purpose of Backtesting: Simulates the strategy on historical data to gauge past performance, offering insights before involving real capital.

  • Diverse Time Periods: Include periods like the COVID-19 crash, present-day data, and both bullish and bearish markets to ensure varied testing scenarios.

  • Backtesting Steps:

    1. Load a Trained Agent: Begin with a previously saved model.
    2. Select Historical Data: Choose a specific period for testing.
    3. Track Performance Metrics: Follow metrics such as profit, drawdown, and sharpe ratio. Record market indicators for each trade.
    4. Run the Backtest: Let the agent trade over the chosen period.
    5. Evaluate Results: Analyze performance metrics and compare with training data.
    6. Adjust Strategy: Refine based on insights and filter out conditions, like high volatility, where the agent underperforms.

The upcoming lessons will delve deeper into encoding backtests in Python.

Supplementary Material - Backtesting

The following Investopedia Article gives a nice refresher of Backtesting.

Backtesting: Definition, How It Works, and Downsides

Why is it important to include various market contexts in your backtesting process?

SOLUTION: To test the strategy's performance under a range of market conditions and assess its robustness

What is a recommended practice when selecting time periods for backtesting?

SOLUTION: Include at least one period of abnormal market behavior, such as COVID-19

What should you do if the backtesting results indicate that the trading strategy is unstable or unprofitable?

SOLUTION: Adjust the strategy based on insights from the backtest and refine it iteratively