Price rising = rumours + good news
Price going down = bad news + panic selling + whales cashing out
But what factors keep Bitcoin price stable?
Actually price can also going down or stable because of rumours too. If the rumours is bad about bitcoin the price can easily down and if there's no bad/good news, the price of bitcoin become stable. The 'Whale' player also contribute about the price.
The whales manipulate the price at unexpected times with huge volume buying and selling transactions. During this they most of the time create a down trend and make use of the opportunity buying as much possible from the users who sell because of the panicked state. The stabilty is gained often with respect to adoption and technology updates.
but to me now it is becoming difficult for the big whale to manipulate the price of bitcoin, and the reason is that the users of bitcoin are increasing from time to time which is now making it difficult for the big whale to manipulate the price of bitcoin so easily.