Double PositionPOST

Places a market order matching the position's symbol, side, and remaining open quantity. When the order fills, the resulting deal is merged into the existing position (VWAP recalculation + quantity increase).

curl -X POST "http://localhost:8081/api/v1/accounts/<string>/positions/pos_123456/double" \
  -H "Authorization: Bearer <token>"

{
  "order_id": "ord_double_123456"
}