Comment by JumpCrisscross

Nobody can transact at the mid-market rate (average of the best bid and best offer). It is a theoretical metric derived from the order book (or at least the portion of the global order book visible to you at the time of calculation - unlike stocks there is no requirement for quotes to be made publicly available). Yes, your bank is making a spread off you but no, not receiving the mid-market rate is not evidence of being screwed.