Bitcoin and Altcoins often do the opposite of each other (but not always). In other words, it is not rare to see Bitcoin go down while alts go up (and vice versa). This is because everyone who has alts has Bitcoin, so they tend to move out of Bitcoin when it goes down and move into alts. With that said, every once in a while this isn’t true and all coins go up or down together (generally following Bitcoin’s lead).
Consider Diversifying. With that above advice in mind, there is nothing worse than getting frustrated with BTC, moving to ETH and missing a price spike, then moving back into BTC and missing the ETH spike. If you have some of your funds in all the coins you trade, you’ll avoid missing out on a unicorn (a term one can use to describe an odd event, like a giant price spike in a short amount of time).
I hope you guy's understand. 