Developers s one of the possible controller of each coin. But the trading platforms dictates the price of each. Some said that the trading platform could be more profitable and powerful than the developer. Since most of the coins are open source, there are lot of people that could have a potential developer of a new more interesting coin. But at the end all those coins will be listed in a trading platform. However, in a trading platform, the traders are the one who could decide what will be potential price of each and every coin. But rumors said that the trading platform could create a dummy accounts which could manipulate the price of a coin. So, who control? The trading platform.