Why Your Backtest Lies: I Got 491% Returns in Testing, Then Broke Even in Production

Why Your Backtest Lies: I Got 491% Returns in Testing, Then Broke Even in Production I deployed a strategy that showed 491% returns in backtests. Three months later: breakeven. The first month was all red. This is not financial advice. This is a post-mortem of my own mistakes, written with $33 worth of lessons learned. Trading crypto carries substantial risk of loss — don't trade with money you can't afford to lose. Credit where it's due: The multi-agent system I use for development is built on @shio_shoppaize 's multi-agent-shogun project. The Setup I built a backtesting engine in Python. Tested 49 strategies on BTC/USDT daily candles, 2023–2026. The top performer — multi_timeframe — returned 546% with a Sharpe of 1.50. Second place was EMA Crossover at 491%. I picked EMA Crossover for live trading. Funded the account with 33 USDT (about $33). Set DRY_RUN=false . Waited. What the Backtest Doesn't Tell You The biggest lie is about execution. In a backtest, every order fills at the clos