Buy the rumor, sell the news. When you see rumor and can verify it with development history or recent activities in development of a project, you can believe in the rumor and do accumulation.
When the news is out, it is time to sell. If it is a news about an event on 15 October and price moves up to much one or two weeks before 15 October, you can sell and take profit. If price moves up like that before events, I am sure it won't rise more on and after the event date.
So the main point is: What's the primary value of Cardano, which defines its price? Technological lead or just speculation?
I am fan of thinking it is technological lead, because when Cardano solves the main issues Ethereum suffers from and constitutes a next development level of blockchain, it may well get a lot of natural demand. And then rumors won't be neccessary to push its price.