Is a Cancel Report required for an unexecuted IOC (Immediate or Cancel) or FOK (Fill or Kill)?
No. An IOC order, by definition, is subject to an immediate partial or full execution. Otherwise, it is automatically partially or fully cancelled. An FOK order, by definition, is subject to either an immediate execution or immediate cancellation. Therefore, it is not necessary to submit to CAT a Cancel Event for an unexecuted order with instructions to be handled as IOC or FOK.