I open a ticket with IBRK for a case of rejected orders. A buy combo order, limit 4, multiplier 100, $2.50 commision, in a cash like account with about $600 settled cash balance, and the order gets rejected with "insufficient funds". After escalation, this is the response: Dear Mr ..., When a limit order is placed far away from the current bid-ask, IB's credit check system will be using the mark price (mid point) for credit check purpose. One of the reason that limit price is not used for credit check calculation is prevent possible cases where exchanges fills the order at the limit price, but later calls in the adjust the contract; claiming the initial fill was out of the line. Your account would end up with the deficit if such adjustment gets made. The limit was not far away from the current bid-ask mid point ( $4.15 at the time ) but anyway, is the "exchange claiming the initial fill was out of the line" a real thing or just support bs?
It's not common but it happens e.g. w/ so called out trades. That said, don't you think you're pushing your margin just a little too much, lol. I mean... any further and you're literally arguing over nickles and dimes!