fix(backtest): classify separated USDC/BUSD pairs (BTC-USDC, ETH/USDC) as crypto

Only the USDT spellings were separator-aware in the market classifier, so
BTC-USDC, ETH/USDC and BTC-BUSD matched no pattern and fell through to the
a_share default (T+1, no shorting, CNY), while the unseparated BTCUSDC and
correlation.infer_market already treated them as crypto.

Signed-off-by: Rudy Celekli <rudy@gradiahq.com>

agent/backtest/engines/_market_hooks.py

@@ -130,6 +130,10 @@ _MARKET_PATTERNS = [
     # perpetual. Bare metals/FX (XAUUSD) end in USD, not USDT/USDC/BUSD, so
     # they still reach the forex whitelist below.
     (re.compile(r"^[A-Z]{2,}(?:USDT|USDC|BUSD)$", re.I), "crypto"),
+    # Separated USDC/BUSD-quoted pairs (BTC-USDC, ETH/USDC). Only the USDT
+    # spellings above were separator-aware, so these fell through to the
+    # a_share default even though the unseparated BTCUSDC is crypto.
+    (re.compile(r"^(?=[A-Z0-9]*[A-Z])[A-Z0-9]+[-/](?:USDC|BUSD)$", re.I), "crypto"),
     # China futures: product+delivery.exchange (e.g. IF2406.CFFEX, rb2410.SHFE)
     # Tushare suffix spellings (SHF/CZC/CFX/GFE) classify here too.
     (

agent/tests/test_crypto_usdc_busd_separated_pairs.py

@@ -0,0 +1,49 @@
+"""Separator-spelled USDC/BUSD crypto pairs must classify as crypto.
+
+``BTCUSDC`` was already crypto, but ``BTC-USDC`` / ``ETH/USDC`` matched no
+pattern and fell through to the ``a_share`` default (T+1, no shorting, CNY,
+tushare) even though ``correlation.infer_market`` already called them crypto.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from backtest.correlation import infer_market
+from backtest.engines._market_hooks import _detect_market, code_currency
+from src.market_data import detect_source
+
+
+@pytest.mark.parametrize(
+    "code",
+    ["BTC-USDC", "ETH/USDC", "SOL-USDC", "BTC-BUSD", "ETH/BUSD", "btc-usdc", "BTCUSDC"],
+)
+def test_separated_usdc_busd_pairs_are_crypto(code: str) -> None:
+    assert _detect_market(code.upper()) == "crypto"
+    assert code_currency(code.upper()) == "USD"
+    assert infer_market(code) == "crypto"
+
+
+@pytest.mark.parametrize("code", ["BTC-USDC", "ETH/USDC", "BTC-BUSD"])
+def test_separated_usdc_busd_pairs_use_the_crypto_source_chain(code: str) -> None:
+    assert detect_source(code) == "okx"
+
+
+@pytest.mark.parametrize(
+    ("code", "market"),
+    [
+        ("USDCAD", "forex"),
+        ("USDCHF", "forex"),
+        ("EUR/USD", "forex"),
+        ("600000", "a_share"),
+        ("000001.SZ", "a_share"),
+        ("AAPL", "us_equity"),
+    ],
+)
+def test_non_crypto_symbols_keep_their_market(code: str, market: str) -> None:
+    assert infer_market(code) == market
+
+
+@pytest.mark.parametrize("code", ["000001-USDC", "000001/BUSD"])
+def test_digit_only_base_is_not_crypto(code: str) -> None:
+    assert _detect_market(code) != "crypto"