--- name: backtesting-py-oracle description: backtesting.py configuration for SQL oracle validation and range bar pattern backtesting. Use when running backtesting.py against. allowed-tools: Read, Bash, Grep, Glob --- # backtesting.py Oracle Validation for Range Bar Patterns Configuration and anti-patterns for using backtesting.py to validate ClickHouse SQL sweep results. Ensures bit-atomic replicability between SQL and Python trade evaluation. **Companion skills**: `clickhouse-antipatterns` (SQL correctness, AP-16) | `sweep-methodology` (sweep design) | `rangebar-eval-metrics` (evaluation metrics) **Validated**: Gen600 oracle verification (2026-02-12) — 3 assets, 5 gates, ALL PASS. --- > **Self-Evolving Skill**: This skill improves through use. If instructions are wrong, parameters drifted, or a workaround was needed — fix this file immediately, don't defer. Only update for real, reproducible issues. ## Critical Configuration (NEVER omit) ```python from backtesting import Backtest bt = Backtest( df, Strategy, cash=100_000, commission=0, hedging=True, # REQUIRED: Multiple concurrent positions exclusive_orders=False, # REQUIRED: Don't auto-close on new signal ) ``` **Why**: SQL evaluates each signal independently (overlapping trades allowed). Without `hedging=True`, backtesting.py skips signals while a position is open, producing fewer trades than SQL. This was discovered when SOLUSDT produced 105 Python trades vs 121 SQL trades — 16 signals were silently skipped. --- ## Anti-Patterns (Ordered by Severity) ### BP-01: Missing Multi-Position Mode (CRITICAL) **Symptom**: Python produces fewer trades than SQL. Gate 1 (signal count) fails. **Root Cause**: Default `exclusive_orders=True` prevents opening new positions while one is active. **Fix**: Always use `hedging=True, exclusive_orders=False`. ### BP-02: ExitTime Sort Order (CRITICAL) **Symptom**: Entry prices appear mismatched (Gate 3 fails) even though both SQL and Python use the same price source. **Root Cause**: `stats._trades` is sorted by ExitTime, not EntryTime. When overlapping trades exit in a different order than they entered, trade[i] no longer maps to signal[i]. **Fix**: ```python trades = stats._trades.sort_values("EntryTime").reset_index(drop=True) ``` ### BP-03: NaN Poisoning in Rolling Quantile (CRITICAL) **Symptom**: Cross-asset tests fail with far fewer Python trades. Feature quantile becomes NaN and propagates forward indefinitely. **Root Cause**: `np.percentile` with NaN inputs returns NaN. If even one NaN feature value enters the rolling window, all subsequent quantiles become NaN, making all subsequent filter comparisons fail. **Fix**: Skip NaN values when building the signal window: ```python def _rolling_quantile_on_signals(feature_arr, is_signal_arr, quantile_pct, window=1000): result = np.full(len(feature_arr), np.nan) signal_values = [] for i in range(len(feature_arr)): if is_signal_arr[i]: if len(signal_values) > 0: window_data = signal_values[-window:] result[i] = np.percentile(window_data, quantile_pct * 100) # Only append non-NaN values (matches SQL quantileExactExclusive NULL handling) if not np.isnan(feature_arr[i]): signal_values.append(feature_arr[i]) return result ``` ### BP-04: Data Range Mismatch (MODERATE) **Symptom**: Different signal counts between SQL and Python for assets with early data (BNB, XRP). **Root Cause**: `load_range_bars()` defaults to `start='2020-01-01'` but SQL has no lower bound. **Fix**: Always pass `start='2017-01-01'` to cover all available data. ### BP-05: Margin Exhaustion with Overlapping Positions (MODERATE) **Symptom**: Orders canceled with insufficient margin. Fewer trades than expected. **Root Cause**: With `hedging=True` and default full-equity sizing, overlapping positions exhaust available margin. **Fix**: Use fixed fractional sizing: ```python self.buy(size=0.01) # 1% equity per trade ``` ### BP-06: Signal Timestamp vs Entry Timestamp (LOW) **Symptom**: Gate 2 (timestamp match) fails because SQL uses signal bar timestamps while Python uses entry bar timestamps. **Root Cause**: SQL outputs the signal detection bar's `timestamp_ms`. Python's `EntryTime` is the fill bar (next bar after signal). These differ by 1 bar. **Fix**: Record signal bar timestamps in the strategy's `next()` method: ```python # Before calling self.buy() self._signal_timestamps.append(int(self.data.index[-1].timestamp() * 1000)) ``` --- ## 5-Gate Oracle Validation Framework | Gate | Metric | Threshold | What it catches | | ---- | --------------- | --------- | ------------------------------------ | | 1 | Signal Count | <5% diff | Missing signals, filter misalignment | | 2 | Timestamp Match | >95% | Timing offset, warmup differences | | 3 | Entry Price | >95% | Price source mismatch, sort ordering | | 4 | Exit Type | >90% | Barrier logic differences | | 5 | Kelly Fraction | <0.02 | Aggregate outcome alignment | **Expected residual**: 1-2 exit type mismatches per asset at TIME barrier boundary (bar 50). SQL uses `fwd_closes[max_bars]`, backtesting.py closes at current bar price. Impact on Kelly < 0.006. --- ## Strategy Architecture: Single vs Multi-Position | Mode | Constructor | Use Case | Position Sizing | | --------------- | -------------------------------------- | --------------------- | ------------------------------ | | Single-position | `hedging=False` (default) | Champion 1-bar hold | Full equity | | Multi-position | `hedging=True, exclusive_orders=False` | SQL oracle validation | Fixed fractional (`size=0.01`) | ### Multi-Position Strategy Template ```python class Gen600Strategy(Strategy): def next(self): current_bar = len(self.data) - 1 # 1. Register newly filled trades and set barriers for trade in self.trades: tid = id(trade) if tid not in self._known_trades: self._known_trades.add(tid) self._trade_entry_bar[tid] = current_bar actual_entry = trade.entry_price if self.tp_mult > 0: trade.tp = actual_entry * (1.0 + self.tp_mult * self.threshold_pct) if self.sl_mult > 0: trade.sl = actual_entry * (1.0 - self.sl_mult * self.threshold_pct) # 2. Check time barrier for each open trade for trade in list(self.trades): tid = id(trade) entry_bar = self._trade_entry_bar.get(tid, current_bar) if self.max_bars > 0 and (current_bar - entry_bar) >= self.max_bars: trade.close() self._trade_entry_bar.pop(tid, None) # 3. Check for new signal (no position guard — overlapping allowed) if self._is_signal[current_bar]: self.buy(size=0.01) ``` --- ## Data Loading ```python from data_loader import load_range_bars df = load_range_bars( symbol="SOLUSDT", threshold=1000, start="2017-01-01", # Cover all available data end="2025-02-05", # Match SQL cutoff extra_columns=["volume_per_trade", "lookback_price_range"], # Gen600 features ) ``` --- ## HTML Equity Plot: Y-Axis Auto-Fit on Zoom (BP-07 to BP-10) backtesting.py generates Bokeh HTML plots via `bt.plot()`. By default, the y-axis is fixed — zooming on the x-axis does NOT rescale the y-axis to fit visible data. This makes it impossible to inspect zoomed-in regions of equity curves that span 4+ orders of magnitude. **Reference implementation**: `scripts/gen800/plotting.py` in opendeviationbar-patterns. ### BP-07: NEVER Use LogScale for Equity (CRITICAL) **Symptom**: Equity panel y-axis doesn't auto-fit on zoom. JS callbacks fail silently. **Root Cause**: Bokeh's `LogScale` breaks `CustomJS` y-range callbacks in multi-panel linked x_range layouts. The `js_on_change` callback fires but `y_range.start`/`y_range.end` assignments are ignored by the LogScale renderer. **Proven via POC**: LogScale + JS callback works in single-panel mode but fails when 5 panels share a linked x_range. **Fix**: Transform equity data to `log10()` in Python, display on **linear** scale with a `CustomJSTickFormatter` that shows `10^tick` as readable values: ```python import numpy as np from bokeh.models import CustomJSTickFormatter, Range1d # Transform data raw = np.asarray(src.data["equity"], dtype=float) raw = np.where(raw > 0, raw, 1e-10) src.data["equity"] = np.log10(raw).tolist() # Custom tick formatter (shows 1%, 100%, 10K%, 1M%) child.yaxis[0].formatter = CustomJSTickFormatter(code=""" const v = Math.pow(10, tick); if (v >= 1e6) return (v/1e6).toFixed(1) + 'M%'; if (v >= 1e3) return (v/1e3).toFixed(0) + 'K%'; if (v >= 1) return v.toFixed(0) + '%'; return v.toFixed(2) + '%'; """) # MUST set initial y_range explicitly (backtesting.py leaves it as NaN) valid = eq[np.isfinite(eq)] pad = (valid.max() - valid.min()) * 0.05 child.y_range = Range1d(start=valid.min() - pad, end=valid.max() + pad) ``` ### BP-08: Panel-Aware Column Matching (CRITICAL) **Symptom**: Drawdown/P&L panels go blank when zooming. Shows millions of percent. **Root Cause**: Multiple panels share the same `ColumnDataSource` (backtesting.py optimization). The Equity panel's Line renderer and the Drawdown panel's Line renderer both reference a source containing `equity`, `drawdown`, `High`, `Low`, etc. A naive "find first y column" approach picks `equity` for the Drawdown panel. **Fix**: Match by `panel_label` FIRST, then by column name: ```python panel_label = child.yaxis[0].axis_label or "" # Label-first matching (panels share data sources!) if "Drawdown" in panel_label and "drawdown" in d: hi_col = lo_col = "drawdown" elif "Equity" in panel_label and "equity" in d: hi_col = lo_col = "equity" elif "High" in d and "Low" in d: # OHLC hi_col, lo_col = "High", "Low" ``` ### BP-09: JS Callback Pattern for Y-Axis Auto-Fit (PROVEN) Attach a `CustomJS` callback to `x_range.js_on_change` for each panel. The callback scans visible data and sets `y_range` directly: ```python from bokeh.models import CustomJS cb = CustomJS( args={"source": src, "yr": child.y_range, "x_col": "index", "y_col": "equity"}, code=""" const xs = source.data[x_col]; const ys = source.data[y_col]; const x0 = cb_obj.start, x1 = cb_obj.end; let lo = Infinity, hi = -Infinity; for (let i = 0; i < xs.length; i++) { if (xs[i] >= x0 && xs[i] <= x1 && isFinite(ys[i])) { if (ys[i] < lo) lo = ys[i]; if (ys[i] > hi) hi = ys[i]; } } if (isFinite(lo) && isFinite(hi) && lo < hi) { const pad = (hi - lo) * 0.05 || 0.001; yr.start = lo - pad; yr.end = hi + pad; } """, ) child.x_range.js_on_change("start", cb) child.x_range.js_on_change("end", cb) ``` ### BP-10: DataRange1d(only_visible=True) Is Unreliable **Symptom**: `DataRange1d(only_visible=True)` works for simple cases but fails with: - LogScale panels (y-range computed in wrong space) - VBar renderers (candlesticks — bounds not tracked correctly) - Shared data sources across panels **Fix**: Always use the JS callback pattern (BP-09) instead of `DataRange1d(only_visible=True)`. ### Panel Data Source Reference (backtesting.py internals) | Panel | Label | Renderer | Y Column | Source | | -------- | ----------------- | ------------------------------------ | ---------------- | --------------------- | | Equity | `"Equity"` | Patch (`equity_dd`), Line (`equity`) | `equity` | Shared OHLC source | | Drawdown | `"Drawdown"` | Line (`drawdown`), Scatter (peak) | `drawdown` | Shared OHLC source | | P/L | `"Profit / Loss"` | Scatter (`returns`), MultiLine | `y` or `returns` | Separate trade source | | OHLC | `""` (no label) | Segment, VBar | `High`/`Low` | Shared OHLC source | | Volume | `"Volume"` | VBar | `Volume` (top) | Shared OHLC source | --- ## Project Artifacts (rangebar-patterns repo) | Artifact | Path | | --------------------------- | ------------------------------------------------- | | Oracle comparison script | `scripts/gen600_oracle_compare.py` | | Gen600 strategy (reference) | `backtest/backtesting_py/gen600_strategy.py` | | SQL oracle query template | `sql/gen600_oracle_trades.sql` | | Oracle validation findings | `findings/2026-02-12-gen600-oracle-validation.md` | | Backtest CLAUDE.md | `backtest/CLAUDE.md` | | ClickHouse AP-16 | `.claude/skills/clickhouse-antipatterns/SKILL.md` | | Fork source | `~/fork-tools/backtesting.py/` | ## Post-Execution Reflection After this skill completes, check before closing: 1. **Did the command succeed?** — If not, fix the instruction or error table that caused the failure. 2. **Did parameters or output change?** — If the underlying tool's interface drifted, update Usage examples and Parameters table to match. 3. **Was a workaround needed?** — If you had to improvise (different flags, extra steps), update this SKILL.md so the next invocation doesn't need the same workaround. Only update if the issue is real and reproducible — not speculative.