Most people fail at it. I remember someone PMing me who got a BTC payout for some work when it had returned to $1000 after all those years. For some reason they wanted me to give them permission to sell it. I told them to sit and wait but they were convinced it was a temporary blip and the price would carry on back down. They wanted out so off they went and were never heard of again.

I don't recall anyone predicting any move that's happened in recent times either. If you'd been furiously trading it more than likely you would now have zilch.