Live Trading with Futures: Invalid Quantity

Ryan, it seems like the issue you're facing with your Interactive Brokers order might be related to the order quantity or other brokerage-specific requirements. Here are a few things to consider:

1. Order Quantity: The error message indicates an invalid quantity of -1. Ensure that the order quantity is valid and meets the minimum lot size requirements for futures contracts. Interactive Brokers enforces specific order size limits, and the quantity should not be less than the lot size.

2. Fractional Trading: Interactive Brokers does not support fractional trading for futures. Ensure that your order does not involve fractional quantities.

3. Brokerage Model Requirements: The brokerage model checks for supported security types, order types, and time-in-force options. Make sure your order complies with these requirements.

4. Order Size Limits: Verify that your order size is within the allowable limits set by Interactive Brokers. The order size must be larger than the minimum order size.

5. Error Code Reference: The error code ORDER_QUANTITY_LESS_THAN_LOT_SIZE (-30) suggests that the order quantity might be less than the required lot size.

Review these aspects of your order and ensure compliance with Interactive Brokers' requirements. If the issue persists, consider reaching out to Interactive Brokers support for further assistance.

Sources: Order Errors - QuantConnect.com, Interactive Brokers - QuantConnect.com

How do you know that the error code is ORDER_QUANTITY_LESS_THAN_LOT_SIZE? Where in the message that I posted does it say or imply that?

Hi Ryan

Some futures have a minimum order size and an order lot size, in which an order must be a whole-number multiple of the lot size that has the quantity above the minimum order size. You can check and adjust the size by:

def on_data(self, slice):
    symbol_properties = self.securities[self.future_symbol].symbol_properties
    # Make it the floor multiple of the lot size
    order_quantity = original_quantity // symbol_properties.lot_size * symbol_properties.lot_size
    # Check if it is above the minimum order size
    if order_quantity >= symbol_properties.minimum_order_size:
        self.market_order(self.future_symbol, order_quantity)

Best
Louis