Pattern Backtest — systematically scan all historical windows matching a return profile. Answers: 'every time {ticker}

Pattern Backtest — systematically scan all historical windows matching a return profile. Answers: 'every time {ticker} did X% over {N} days, what happened in the next {M} days?' HOW TO CALL: POST /pattern_backtest?ticker=SPY&lookback_days=20&min_return=-0.05&max_return=0.0&forward_days=30 PARAMETERS: ticker — asset symbol (required) lookback_days — window length to scan (default 20) min_return — minimum window return, decimal (e.g. -0.05 = -5%; default: no bound) max_return — maximum window return, decimal (e.g. 0.10 = +10%; default: no bound) forward_days — forward horizon to measure (default 30) RESPONSE: occurrences (count of matching windows), forward_return_distribution (p10/p25/p50/p75/p90 + mean/stdev/pct_positive), example_windows. PRICING: $0.50 per call.