Yes, these crashes in prices are only done to manipulate the investors but in actual, these crashes do not realize the decentralization of bitcoin but done in order to increase the exchanges leading to investors loss. Many strategic investors know the true reason behind these crashes and they are not too much afraid although, their interest and optimism in making the profit increases. And those result as the luckiest in trading. Hence, we should learn the lesson from the loses done by us and also from these investors.