max_drawdown
Calculate maximum drawdown to assess portfolio risk by measuring the largest peak-to-trough decline in value, helping identify potential losses during market downturns.
Instructions
Calculates Maximum Drawdown.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Implementation Reference
- tools/risk_engine.py:62-75 (handler)The core handler function implementing the max_drawdown tool. Computes the maximum drawdown of the portfolio using historical price data fetched via yfinance and position weights.
def max_drawdown() -> str: """Calculates Maximum Drawdown.""" data, weights = _get_portfolio_data() if data is None: return "Portfolio is empty." returns = data.pct_change().dropna() port_returns = returns.dot(weights) cumulative_returns = (1 + port_returns).cumprod() peak = cumulative_returns.expanding(min_periods=1).max() drawdown = (cumulative_returns / peak) - 1 max_dd = drawdown.min() return f"Maximum Drawdown: {max_dd:.2%}" - tools/risk_engine.py:10-30 (helper)Helper function that retrieves portfolio positions, downloads historical price data using yfinance, and computes value-based weights. Used by max_drawdown and other risk tools.
def _get_portfolio_data(lookback: str = "1y"): portfolio = get_positions() positions = portfolio.get("positions", {}) if not positions: return None, None tickers = list(positions.keys()) weights = np.array(list(positions.values())) # This is qty, need value weights # Fetch data data = yf.download(tickers, period=lookback, progress=False)['Close'] if isinstance(data, pd.Series): data = data.to_frame(name=tickers[0]) # Calculate current value weights current_prices = data.iloc[-1] values = current_prices * pd.Series(positions) total_value = values.sum() weights = values / total_value return data, weights - server.py:380-383 (registration)Registration of the max_drawdown tool (along with related risk tools) to the FastMCP server using the register_tools helper.
register_tools( [portfolio_risk, var, max_drawdown, monte_carlo_simulation], "Risk Engine" ) - server.py:14-14 (registration)Import statement bringing the max_drawdown function into the MCP server module for registration.
from tools.risk_engine import portfolio_risk, var, max_drawdown, monte_carlo_simulation