feat(portfolio): track realized PnL on sell orders

1 files changed, 11 insertions, 2 deletions

diff --git a/services/portfolio-manager/src/portfolio_manager/portfolio.py b/services/portfolio-manager/src/portfolio_manager/portfolio.py
index 2c93643..4a7a11f 100644
--- a/services/portfolio-manager/src/portfolio_manager/portfolio.py
+++ b/services/portfolio-manager/src/portfolio_manager/portfolio.py
@@ -18,6 +18,11 @@ class PortfolioTracker:
 
     def __init__(self) -> None:
         self._positions: dict[str, _PositionState] = {}
+        self._realized_pnl: Decimal = Decimal("0")
+
+    @property
+    def realized_pnl(self) -> Decimal:
+        return self._realized_pnl
 
     def _get_or_create(self, symbol: str) -> _PositionState:
         if symbol not in self._positions:
@@ -35,8 +40,12 @@ class PortfolioTracker:
             if state.quantity > Decimal("0"):
                 state.avg_entry = total_cost / state.quantity
         elif order.side == OrderSide.SELL:
-            state.quantity -= order.quantity
-            # Keep avg_entry unchanged unless fully sold
+            # Calculate realized PnL for this sell
+            sell_quantity = min(order.quantity, state.quantity)
+            if sell_quantity > 0 and state.avg_entry > 0:
+                self._realized_pnl += sell_quantity * (order.price - state.avg_entry)
+
+            state.quantity -= sell_quantity
             if state.quantity <= Decimal("0"):
                 state.quantity = Decimal("0")
                 state.avg_entry = Decimal("0")