walk_forward_analysis

Instructions

Implementation Reference

• tools/backtesting.py:172-245 (handler)

  Main handler function implementing walk-forward analysis for MA crossover strategy. Fetches data, creates rolling train/test windows, optimizes MA parameters on train data, evaluates on test data, and compiles results.

  def walk_forward_analysis(symbol: str, start_date: str = "2020-01-01", end_date: str = "2023-12-31", train_months: int = 12, test_months: int = 3) -> str:
      """
      Performs Walk Forward Analysis on MA Crossover.
      Optimizes (Fast, Slow) on Train, tests on Test.
      """
      df = _fetch_data(symbol, start_date, end_date)
      if df.empty:
          return "No data found."
      
      close = df['Close']
      if isinstance(close, pd.DataFrame):
          close = close.iloc[:, 0]
          
      # Generate windows
      # Simplified: Iterate by index assuming daily data
      # 21 days/month
      train_len = train_months * 21
      test_len = test_months * 21
      step = test_len
      
      results = []
      
      # Parameter Grid
      fast_params = [10, 20, 50]
      slow_params = [50, 100, 200]
      
      current_idx = 0
      while current_idx + train_len + test_len < len(df):
          train_data = close.iloc[current_idx : current_idx + train_len]
          test_data = close.iloc[current_idx + train_len : current_idx + train_len + test_len]
          
          # Optimize on Train
          best_perf = -np.inf
          best_params = (0, 0)
          
          for f in fast_params:
              for s in slow_params:
                  if f >= s: continue
                  # Vectorized backtest on train
                  fast_ma = train_data.rolling(window=f).mean()
                  slow_ma = train_data.rolling(window=s).mean()
                  signal = (fast_ma > slow_ma).astype(int).shift(1)
                  ret = train_data.pct_change() * signal
                  perf = ret.sum() # Simple sum of returns
                  
                  if perf > best_perf:
                      best_perf = perf
                      best_params = (f, s)
          
          # Test on Test Data
          f, s = best_params
          fast_ma_test = test_data.rolling(window=f).mean()
          slow_ma_test = test_data.rolling(window=s).mean()
          signal_test = (fast_ma_test > slow_ma_test).astype(int).shift(1)
          ret_test = test_data.pct_change() * signal_test
          test_perf = ret_test.sum()
          
          results.append({
              "Period": f"{test_data.index[0].date()} to {test_data.index[-1].date()}",
              "Best Params": best_params,
              "Test Return": test_perf
          })
          
          current_idx += step
          
      # Format Output
      output = ["Walk Forward Analysis Results:"]
      total_ret = 0
      for r in results:
          output.append(f"[{r['Period']}] Params: {r['Best Params']}, Return: {r['Test Return']:.2%}")
          total_ret += r['Test Return']
          
      output.append(f"Total Walk Forward Return: {total_ret:.2%}")
      return "\n".join(output)

• server.py:384-388 (registration)

  MCP tool registration of walk_forward_analysis (with run_backtest) in the 'Backtesting' category via register_tools function.

  register_tools(
      [run_backtest, walk_forward_analysis],
      "Backtesting"
  )

• app.py:289-291 (registration)

  Inclusion of walk_forward_analysis in the Gradio UI toolbox under 'Backtesting' category (supports MCP server mode).

  "Risk Management": [portfolio_risk, var, max_drawdown, monte_carlo_simulation],
  "Backtesting": [run_backtest, walk_forward_analysis],
  "Technical Analysis": [compute_indicators, rolling_stats, get_technical_summary],

• tools/backtesting.py:172-176 (schema)

  Type hints and docstring defining input parameters (symbol, dates, train/test months) and str output for the tool.

  def walk_forward_analysis(symbol: str, start_date: str = "2020-01-01", end_date: str = "2023-12-31", train_months: int = 12, test_months: int = 3) -> str:
      """
      Performs Walk Forward Analysis on MA Crossover.
      Optimizes (Fast, Slow) on Train, tests on Test.
      """