The default order type is symbol type specific and is really for trade ticket only. The order type that chart trading orders, the order type always defaults to Limit. You could hit the T key while in "drop mode" for the order to toggle through the different order types, so if using IB and wish to get to Market, you would hit T 7 times. May sound inefficient, but if you do that often, you can do it in a sec. However, it would be faster to just drop the buy order above the current price (or sell order below the current price). Has basically the same result and is much faster