Lol it already is, everyone manipulates and goes wild, look at the exchanges one happens to be $100 over everyone else. Now ask yourself why.
everyone ? no i dont think so . not all have the power to manipulate the price but except from whales because they are known to be rich . they can buy or sell in bigger volume's resulting for the value to experience a drastic change .
Holding crypto assets in exchanges is not a good practice because there are many manipulators in exchanges who tries to change the market price for there advantage which destroy the balance of a currency and make losses for honest investors but still cryptocurrency investment is a profitable one if done with patience and proper understanding
what about holding crypto assets in a online wallet ? do you think thats more safer than storing your coins on an exchange ? both are the same because all kind of wallets can potentially be hacked but that wont likely occur as long as the platform that you are using is known to be legit but manipulators arent destroying the balance of the scale . the act of manipulation is pretty normal and infact it can be also an advantage .