Its a very simple system an any cryptocurrency are listed in two exchange some time one place price and another price are Change so a people buy a low and they sell these are another exchange that is buying low and sell high system.
I did not comprehend you well, but what i want to emphasis base on your comment, is that no investor who is not suppose to think higher towards investment, right away the expectations of every investor is to ensure that it succeeded in making profit in any of it's investment. So every investor like buying low and sell at higher rate to make profit. So that is the primary concern of any investor.