---
name: stock-backtest
description: Design, run, and interpret strategy backtests for A-share stocks
---

## What I Do

Guide the agent through backtesting trading strategies:
1. Help design strategy rules from user descriptions
2. Run backtests on historical data
3. Interpret results and identify potential issues
4. Suggest improvements

## Capital Context (CRITICAL)

**The user has ~5万 RMB capital.** Backtest interpretation must be capital-aware:

- When presenting metrics, translate key numbers to the user's context:
  - "Annualized return 15% = ¥7,500 on 5万"
  - "Max drawdown 12% = ¥6,000 worst-case loss"
  - "Average win ¥800, average loss ¥1,200 per trade"
- Assess whether a strategy is **practically usable** with 5万 considering position sizing constraints
- Flag if a strategy requires more positions than 5万 can support

## Key Backtest Metrics

- **Cumulative return**: total return over the period
- **Annualized return**: normalized yearly return (translate to ¥ on 5万)
- **Win rate**: percentage of profitable trades
- **Max drawdown**: worst peak-to-trough decline (translate to ¥)
- **Sharpe ratio**: risk-adjusted return
- **Benchmark comparison**: vs CSI 300 index

## Strategy Parameters

Common strategy elements to help users define:
- Entry conditions (e.g., MA crossover, breakout, pullback)
- Exit conditions (e.g., stop loss %, take profit %, trailing stop, time-based)
- Position sizing (e.g., fixed %, Kelly fraction)
- Test period and stock universe

## When to Use Me

Use when the user asks to:
- Backtest a trading strategy
- Verify a strategy's historical performance
- Compare multiple strategies
- Evaluate whether a strategy is worth using

## Workflow

1. Clarify strategy rules with user
2. Translate rules into testable parameters
3. Run backtest via `stock-backtest` tools
4. Present results with interpretation:

### Output Format

1. **Strategy Summary**: rules in plain language
2. **Performance Metrics**: all key metrics in table form
3. **Capital Context Translation**:
   | Metric | Value | On 5万 Capital |
   |--------|-------|----------------|
   | Annualized Return | 18% | ¥9,000/year |
   | Max Drawdown | 15% | ¥7,500 worst case |
   | Avg Win per Trade | ¥450 | — |
   | Avg Loss per Trade | ¥600 | — |
4. **Equity Curve Description**: shape, drawdown periods, recovery time
5. **Benchmark Comparison**: outperformance/underperformance vs CSI 300
6. **Practicality Assessment for 5万**: 
   - Can the user afford the position sizes?
   - Does the strategy require too many concurrent positions?
   - Is the max drawdown psychologically tolerable?
7. **Potential Concerns**: overfitting, look-ahead bias, survivorship bias, regime dependence

## Risk Disclaimer

Always remind: backtest results reflect historical data. Live performance will differ. Strategies can fail in new market regimes. The user bears all trading risk.