If the ecosystem has decided one exchange is the lead price, then they manipulate the price without needing the underlying assets.
Furthermore, bitcoin is one of the only markets I've seen which rewards "whales" instead of punishing them, because in most markets moving the market you will lose money to slippage. The market price will retract after you bump it. In bitcoin markets if you move out the price no-one is trading the 'fundamentals' so it just stays at the new price. Instead of losing money to slippage you gain money from it.
Magic internet money indeed!