BTC is going up because it is hitting the mainstream but at the moment it is facing some correction.
This failure of rising fast enough makes everybody who understands cryptos to move to other cryptcurrencies like Daesh, BCH or others try to loose less money while BTC goes down and maybe going back when the proce rises again.
BTC has some problems like the high fees which makes it not attractive to be a used as a real currency. But many exchanges uses it as dollar is used in the world. So BTC is the old crypto which everyone needs sometimes to trade but many intelligent people are not trusting the hype of BTC and if you are smart you go directly in the right alternative cryptocurrency like Litecoin, Ethereum, Daesh, ...
But it is difficult to say which one will perform best in the future.
At the moment a lot of new money is coming into the market. That's why all prices are rising...