Sell BNB at 650 and buy after dip = unlimited money?

I hold a lot of Bnb because of Binance launchpads but as I see everytime Bnb jumps up, it falls damn fast. Like every dip it fells from 650$ to >600 - 500$ or below. What if I buy at the 500$ levels and sell again at 650$?
The white line is 650$. Maybe a Sell order at that point? And then some buy orders at 620, 600, 590, 580...