Quote from the1:
I've trade a wide variety of futures contracts at small and large sizes and the difference between trying to exit 1 lot vs 50 lots can be like the difference between swimming the English Channel compared to swimming the length of the pool in your back yard. If you system works with 1 lot sizing up to 50 lots will make a huge difference, especially if you find yourself in a counter-trend trade. There are times when exiting 1 lot will be the same as 50 but others when those extra 49 lots just aren't available at that price. You either take the slippage or you wait for the market to come back. Both can be very uncomfortable.