It depends upon the coin because most of the coin prices will increase after listing ...........
I am not sure if you have a basis on what you are saying or just your own opinion.
IMO, it depends on the timing of listing because if you list in a bearish market, you can't expect that the price will rise, and per reality, most of the coins that are listed in the past have drop their value after getting listed in an exchange, but during the bull run in 2017, they do rise and even rise beyond our expectation.