One unique aspect of trading is that one does not see the other side of his trade (unlike in real world where one could generally see the person one trades with). If one were to know whether the other side is a long closing a winning, flat or a losing trade (3 cases here), and in the case of shorts opening a new trade would this information help in building an edge? If yes, how and why?
Example: what if one were to buy only from one type of opposite trader (see 4 cases above)?
Example: what if one were to buy only from one type of opposite trader (see 4 cases above)?

