How to Check Your Cash Balance for a Specific Currency in QuantConnect

To check your available USDT balance in a QuantConnect strategy, you should access the cash_book object within the portfolio.

The specific property is self.portfolio.cash_book["USDT"].amount.

Below is a complete, runnable example demonstrating how to check the USDT balance before placing an order for a crypto pair (e.g., BTCUSDT).

Implementation Details

1. Access Portfolio: Use self.portfolio.
2. Access CashBook: Use .cash_book.
3. Select Currency: Index with the string ticker of the currency, e.g., ["USDT"].
4. Get Amount: Use the .amount property.

Code Example

from AlgorithmImports import *

class CryptoBalanceCheckAlgorithm(QCAlgorithm):

    def initialize(self):
        self.set_start_date(2023, 1, 1)
        self.set_end_date(2023, 2, 1)
        
        # Set account currency to USDT for simplicity (optional, but common in crypto-only strats)
        self.set_account_currency("USDT")
        self.set_cash(10000)
        
        # Set Brokerage Model (e.g., Binance, Bybit)
        self.set_brokerage_model(BrokerageName.BINANCE, AccountType.MARGIN)
        
        # Add Crypto Pair
        self.symbol = self.add_crypto("BTCUSDT", Resolution.MINUTE).symbol
        
        # Minimum USDT required to trade
        self.min_usdt_balance = 1000

    def on_data(self, data: Slice):
        if not self.portfolio.invested:
            # ---------------------------------------------------
            # CHECK USDT BALANCE HERE
            # ---------------------------------------------------
            # Ensure the key "USDT" exists in the cash_book before accessing
            if "USDT" in self.portfolio.cash_book:
                available_usdt = self.portfolio.cash_book["USDT"].amount
                
                self.log(f"Current USDT Balance: {available_usdt}")

                # Logic: Only buy if we have more than the minimum required balance
                if available_usdt > self.min_usdt_balance:
                    # Calculate quantity to buy with 50% of available USDT
                    # We use available_usdt explicitly in the calculation
                    quantity = (available_usdt * 0.5) / data[self.symbol].close
                    self.buy(self.symbol, quantity)
                    self.log(f"Buying {quantity} BTC with USDT")
                else:
                    self.log("Insufficient USDT to place trade.")

Key Considerations

• Currency Ticker: Ensure you use the correct ticker string. For Tether, it is "USDT". If you are trading USD pairs (e.g., BTCUSD on Coinbase), the cash is likely in "USD".
• Settled vs. Unsettled: self.portfolio.cash_book["USDT"].amount returns the total cash. If you are trading in a margin account, this is usually immediately available. If you need to check specifically for settled cash (rare in standard crypto backtests but relevant in some contexts), you can check self.portfolio.unsettled_cash_book.
• Buying Power: While checking the cash balance is useful, it does not account for margin requirements or leverage. If you want to know how much you can buy including leverage, use:

  buying_power = self.portfolio.get_buying_power(self.symbol, OrderDirection.BUY)
  

Q&A

Q: What happens if I try to access a currency that I don't own in cash_book?
A: If you try to access self.portfolio.cash_book["ETH"] but have never held ETH, it may raise a KeyError. It is best practice to check if "ETH" in self.portfolio.cash_book: or use .get("ETH") which allows handling cases where the key is missing.

Q: Does cash_book["USDT"].amount include the value of my open positions?
A: No. .amount strictly represents the uninvested cash sitting in the account. To see the total value of your account (Cash + Unrealized Profit/Loss + Position Value), use self.portfolio.total_portfolio_value.

Q: How do I check the conversion rate of my USDT to the account base currency?
A: If your account is in USD but you hold USDT, you can check the conversion rate using self.portfolio.cash_book["USDT"].conversion_rate.