Building a Crypto Trading Bot from Scratch - 12: Position Tracking

Knowing Where You Stand

After placing orders through the Trade Executor, you’d think the hard part is done. But actually, that’s when a new challenge begins: tracking your positions.

How much are you up or down on each trade? Has any position hit its stop loss? Is it time to take a profit? How much total capital do you have at risk right now?

Without a Position Manager to answer these questions, you’re flying blind. You might think you’re profitable when you’re actually down. You might miss stop losses and watch small losses become big ones.

This is what the Position Manager solves. It’s your accounting system, your P&L calculator, and your exit condition monitor, all in one.

What Is a Position?

A position represents an open trade. When you buy 0.02 BTC at $50,000, you have a long position. When you sell it (hopefully at $52,000), the position closes.

Here’s what we track for each position:

@dataclass
class Position:
    position_id: str
    symbol: str
    strategy_name: str
    side: PositionSide  # LONG or SHORT
    entry_price: float
    quantity: float
    entry_time: datetime
    stop_loss: Optional[float] = None
    take_profit: Optional[float] = None
    unrealized_pnl: float = 0.0  # Current paper profit/loss
    realized_pnl: float = 0.0    # Actual profit/loss when closed
    entry_fee: float = 0.0       # Fee paid on entry

Unrealized P&L: How much you’d make/lose if you closed now (paper profit) Realized P&L: Actual profit/loss from closed positions (real money)

This distinction matters. Unrealized P&L fluctuates with the market. Realized P&L only changes when you actually close positions.

The Position Manager

Here’s the core structure: