It seems to me that the price drop after the listing is due to the fact that no one believes in the value of coins in the future, since every investor, as well as the Bounty Hunter, only plans to make money on a certain project, and few people worry about the future of this company. Recently, a lot of companies have announced that their tokens that they issued do not have a practical purpose. Therefore, everyone is trying to get rid of these coins as soon as possible.
Its not that investors dont have confidence in any coin. If the price drops when adding a coin to the exchange, this may be due to a general crisis in the cryptocurrency market or trading speculations. Someone from a major player is trying to artificially reduce the price of a cryptocurrency asset.
After listing on the exchange the price of a coin should increase, but we are seeing in the reverse form after listing the coin price will decrease because most of the investors will look for short term profits, they won't bother about their future returns. So there are very few people who have strong faith will hold the coins.