Flatten First
A PLACE order command with the flatten_first flag enabled is the most popular alert type at CrossTrade, and for good reason.
Flatten first tells CrossTrade that you want to preempt the PLACE order command with a CLOSEPOSITION command for the same account and instrument.
When flatten_first=true, CrossTrade will first send the CLOSEPOSITION command, which flattens any existing positions or open orders for the underlying instrument. Regardless of whether or not a position existed, the PLACE order command will then proceed.
This behavior is contrast to the REVERSEPOSITION command, which will only proceed with the new order instructions if and only if a position already exists in the underlying instrument.
Flatten first is useful for peace of mind to ensure you are always entering the market flat.
Important Note: flatten_first will cancel open or pending orders in the account even if a position does not exist that can be flattened. This behavior is distinctly different from a CLOSEPOSITION or FLATTEN command.
Example Payload
The following command will close any positions or orders in ES 06-26 under the sim101 account before proceeding with the market buy for 1 contract:
key=your-secret-key;
command=place;
account=sim101;
instrument=ES 06-26;
action=buy;
qty=1;
order_type=market;
tif=day;
flatten_first=true;