fix: correct short-side tie-break semantics in triple barrier

src/analysis/triple_barrier.py

@@ -0,0 +1,111 @@
+"""Triple barrier labeler utilities.
+
+Implements first-touch labeling with upper/lower/time barriers.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Literal, Sequence
+
+
+TieBreakMode = Literal["stop_first", "take_first"]
+
+
+@dataclass(frozen=True)
+class TripleBarrierSpec:
+    take_profit_pct: float
+    stop_loss_pct: float
+    max_holding_bars: int
+    tie_break: TieBreakMode = "stop_first"
+
+
+@dataclass(frozen=True)
+class TripleBarrierLabel:
+    label: int  # +1 take-profit first, -1 stop-loss first, 0 timeout
+    touched: Literal["take_profit", "stop_loss", "time"]
+    touch_bar: int
+    entry_price: float
+    upper_barrier: float
+    lower_barrier: float
+
+
+def label_with_triple_barrier(
+    *,
+    highs: Sequence[float],
+    lows: Sequence[float],
+    closes: Sequence[float],
+    entry_index: int,
+    side: int,
+    spec: TripleBarrierSpec,
+) -> TripleBarrierLabel:
+    """Label one entry using triple-barrier first-touch rule.
+
+    Args:
+        highs/lows/closes: OHLC components with identical length.
+        entry_index: Entry bar index in the sequences.
+        side: +1 for long, -1 for short.
+        spec: Barrier specification.
+    """
+    if side not in {1, -1}:
+        raise ValueError("side must be +1 or -1")
+    if len(highs) != len(lows) or len(highs) != len(closes):
+        raise ValueError("highs, lows, closes lengths must match")
+    if entry_index < 0 or entry_index >= len(closes):
+        raise IndexError("entry_index out of range")
+    if spec.max_holding_bars <= 0:
+        raise ValueError("max_holding_bars must be positive")
+
+    entry_price = float(closes[entry_index])
+    if entry_price <= 0:
+        raise ValueError("entry price must be positive")
+
+    if side == 1:
+        upper = entry_price * (1.0 + spec.take_profit_pct)
+        lower = entry_price * (1.0 - spec.stop_loss_pct)
+    else:
+        # For short side, favorable move is down.
+        upper = entry_price * (1.0 + spec.stop_loss_pct)
+        lower = entry_price * (1.0 - spec.take_profit_pct)
+
+    last_index = min(len(closes) - 1, entry_index + spec.max_holding_bars)
+    for idx in range(entry_index + 1, last_index + 1):
+        h = float(highs[idx])
+        l = float(lows[idx])
+
+        up_touch = h >= upper
+        down_touch = l <= lower
+        if not up_touch and not down_touch:
+            continue
+
+        if up_touch and down_touch:
+            if spec.tie_break == "stop_first":
+                touched = "stop_loss"
+                label = -1
+            else:
+                touched = "take_profit"
+                label = 1
+        elif up_touch:
+            touched = "take_profit" if side == 1 else "stop_loss"
+            label = 1 if side == 1 else -1
+        else:
+            touched = "stop_loss" if side == 1 else "take_profit"
+            label = -1 if side == 1 else 1
+
+        return TripleBarrierLabel(
+            label=label,
+            touched=touched,
+            touch_bar=idx,
+            entry_price=entry_price,
+            upper_barrier=upper,
+            lower_barrier=lower,
+        )
+
+    return TripleBarrierLabel(
+        label=0,
+        touched="time",
+        touch_bar=last_index,
+        entry_price=entry_price,
+        upper_barrier=upper,
+        lower_barrier=lower,
+    )

tests/test_triple_barrier.py

@@ -0,0 +1,131 @@
+from __future__ import annotations
+
+from src.analysis.triple_barrier import TripleBarrierSpec, label_with_triple_barrier
+
+
+def test_long_take_profit_first() -> None:
+    highs = [100, 101, 103]
+    lows = [100, 99.6, 100]
+    closes = [100, 100, 102]
+    spec = TripleBarrierSpec(take_profit_pct=0.02, stop_loss_pct=0.01, max_holding_bars=3)
+    out = label_with_triple_barrier(
+        highs=highs,
+        lows=lows,
+        closes=closes,
+        entry_index=0,
+        side=1,
+        spec=spec,
+    )
+    assert out.label == 1
+    assert out.touched == "take_profit"
+    assert out.touch_bar == 2
+
+
+def test_long_stop_loss_first() -> None:
+    highs = [100, 100.5, 101]
+    lows = [100, 98.8, 99]
+    closes = [100, 99.5, 100]
+    spec = TripleBarrierSpec(take_profit_pct=0.02, stop_loss_pct=0.01, max_holding_bars=3)
+    out = label_with_triple_barrier(
+        highs=highs,
+        lows=lows,
+        closes=closes,
+        entry_index=0,
+        side=1,
+        spec=spec,
+    )
+    assert out.label == -1
+    assert out.touched == "stop_loss"
+    assert out.touch_bar == 1
+
+
+def test_time_barrier_timeout() -> None:
+    highs = [100, 100.8, 100.7]
+    lows = [100, 99.3, 99.4]
+    closes = [100, 100, 100]
+    spec = TripleBarrierSpec(take_profit_pct=0.02, stop_loss_pct=0.02, max_holding_bars=2)
+    out = label_with_triple_barrier(
+        highs=highs,
+        lows=lows,
+        closes=closes,
+        entry_index=0,
+        side=1,
+        spec=spec,
+    )
+    assert out.label == 0
+    assert out.touched == "time"
+    assert out.touch_bar == 2
+
+
+def test_tie_break_stop_first_default() -> None:
+    highs = [100, 102.1]
+    lows = [100, 98.9]
+    closes = [100, 100]
+    spec = TripleBarrierSpec(take_profit_pct=0.02, stop_loss_pct=0.01, max_holding_bars=1)
+    out = label_with_triple_barrier(
+        highs=highs,
+        lows=lows,
+        closes=closes,
+        entry_index=0,
+        side=1,
+        spec=spec,
+    )
+    assert out.label == -1
+    assert out.touched == "stop_loss"
+
+
+def test_short_side_inverts_barrier_semantics() -> None:
+    highs = [100, 100.5, 101.2]
+    lows = [100, 97.8, 98.0]
+    closes = [100, 99, 99]
+    spec = TripleBarrierSpec(take_profit_pct=0.02, stop_loss_pct=0.01, max_holding_bars=3)
+    out = label_with_triple_barrier(
+        highs=highs,
+        lows=lows,
+        closes=closes,
+        entry_index=0,
+        side=-1,
+        spec=spec,
+    )
+    assert out.label == 1
+    assert out.touched == "take_profit"
+
+
+def test_short_tie_break_modes() -> None:
+    highs = [100, 101.1]
+    lows = [100, 97.9]
+    closes = [100, 100]
+
+    stop_first = TripleBarrierSpec(
+        take_profit_pct=0.02,
+        stop_loss_pct=0.01,
+        max_holding_bars=1,
+        tie_break="stop_first",
+    )
+    out_stop = label_with_triple_barrier(
+        highs=highs,
+        lows=lows,
+        closes=closes,
+        entry_index=0,
+        side=-1,
+        spec=stop_first,
+    )
+    assert out_stop.label == -1
+    assert out_stop.touched == "stop_loss"
+
+    take_first = TripleBarrierSpec(
+        take_profit_pct=0.02,
+        stop_loss_pct=0.01,
+        max_holding_bars=1,
+        tie_break="take_first",
+    )
+    out_take = label_with_triple_barrier(
+        highs=highs,
+        lows=lows,
+        closes=closes,
+        entry_index=0,
+        side=-1,
+        spec=take_first,
+    )
+    assert out_take.label == 1
+    assert out_take.touched == "take_profit"