Transparency is something majority of this project do not have. This is why they can easily dump their tokens in the market and nobody will realized the dumps are from the exchange. The rumors will be some whale has dump not knowing it's all the doings of the project. Lack of transparency is also why we have inside trading ongoing with in the projects.
Have you wondered why a project pumps suddenly before a news is realize about an update or upcoming events for the project, it has to be inside trading that caused it. This inside trading can be notice before an exchange listing especially those with large audience and reputation like Binance, Coinbase etc.