Bitfinex became frequent with pamp and dump. Yesterday there was a serious manipulation of 3 coins: NEO, ETP, OMG. Many people who were in marginal trading went into big minus. You can enter the exchange and see how the prices for these tokens have been omitted several times in a matter of minutes. Why such a large exchange creates manipulation and undermines trust? Or the exchange is not to blame?
If someone wants to use their money to try and manipulate the market, why should an exchange interfere? It's market processes at work. Even BTC is not immune to this kind of activity. People tried to pump & dump BCash at the fork. It's a fact of life in crypto and not the problem of just one exchange. It happens everywhere, even in traditional stock markets.