{
  "source_label": "market-research A-share rule reconstruction",
  "method": "smallest 400 by market cap, equal weight, next market day return",
  "observations": 2838,
  "max_drawdown": -0.5127186139467239,
  "longest_underwater_trading_days": 317,
  "longest_underwater_start": "2017-11-13",
  "longest_underwater_end": "2019-03-04",
  "underwater_episode_count": 149,
  "caveats": [
    "Research reconstruction, not Wind 8841431.WI official index.",
    "No transaction costs, limit handling, or strategy capacity simulation."
  ]
}