fix(portfolio): refuse a portfolio with a number that is not finite (#1509)

- cash, quantities and average prices reject NaN and infinity when the file loads

tests/test_portfolio_context.py

@@ -96,6 +96,20 @@ def test_a_holding_keeps_the_instrument_it_was_listed_as():
     assert "Other positions: WTI 100" in text and "CL=F" not in text
 
 
+@pytest.mark.unit
+@pytest.mark.parametrize("book", [
+    '{"cash": NaN}',
+    '{"positions": [{"ticker": "AAPL", "quantity": Infinity}]}',
+    '{"positions": [{"ticker": "AAPL", "quantity": 1, "average_price": "nan"}]}',
+])
+def test_load_rejects_a_number_that_is_not_finite(tmp_path, book):
+    # Python's json writes NaN and Infinity, and they would reach the agents as "nan units".
+    bad = tmp_path / "p.json"
+    bad.write_text(book)
+    with pytest.raises(ValueError, match="portfolio"):
+        load_portfolio(bad)
+
+
 @pytest.mark.unit
 def test_load_reads_a_valid_file(tmp_path):
     good = tmp_path / "p.json"

tradingagents/portfolio.py

@@ -17,18 +17,22 @@ import hashlib
 import json
 from pathlib import Path
 
-from pydantic import BaseModel, Field, ValidationError
+from pydantic import BaseModel, ConfigDict, Field, ValidationError
 
 from tradingagents.dataflows.symbols import normalize_symbol
 
 
 class Position(BaseModel):
+    model_config = ConfigDict(allow_inf_nan=False)
+
     ticker: str = Field(description="Instrument symbol, e.g. AAPL")
     quantity: float = Field(description="Signed units held; negative is short")
     average_price: float | None = Field(default=None, description="Average entry price per unit")
 
 
 class PortfolioContext(BaseModel):
+    model_config = ConfigDict(allow_inf_nan=False)
+
     cash: float | None = Field(default=None, description="Free cash available")
     currency: str | None = Field(default=None, description="Currency label for cash and prices")
     positions: list[Position] = Field(default_factory=list)