The price of Ethereum will not go up forever, nor will it forever go down, After a few days ago it went up and yesterday went down, Today's Ethereum price went up again. That's a natural thing in Cryptocurrency, and that's what it's called Crypto price fluctuations. And because of that, Cryptocurrency investors and traders can get a profit, because they wait for the price to fall to buy it then they sell it when the price goes up.