Which Exchange Code will Dropcopy FIX sessions receive in the execution report?

VIEW TRADE CONFIRMATION REPORTS

You will get a notice of the option assignment sent to your Message Center and your Trade Confirmation report will have the closing option transactions and any resulting stock transactions in the Trades section,…

If you receive an order reject for a “Large Size” order you will need to recreate a new order for a smaller amount. Due to regulatory obligations, and in an effort to prevent sending orders to an exchange that would be disruptive to the marketplace, IBKR has implemented filters for "Large Sized" orders. These filters are based on the Average Daily Volume from the reporting exchanges. If your order is affected then the reject message will recommend a smaller amount for a new order that would fall within the "Large Size" order check parameters.     …

No. FIX clients are not required to send new exchange codes immediately. IBKR will try to resolve the contract based on the exchange received from the FIX client. If the provided exchange code is one of the old codes, IBKR will automatically switch to the new exchange code to resolve the contract. When IBKR sends back the order status and trades, the original exchange code received from the client will be provided…

IBKR will automatically correct the Exchange code in the following tags. Client will receive their sent exchange code in execution reports, except on Dropcopy sessions.