As we can see, most of all altcoins was relying upon Bitcoin price movement, when Bitcoin goes down all altcoins goes down too.
I suggest giving full support to Bitcoin and I think the most reasonable dividend of investment is 90% for Bitcoin and the rest is for altcoins or as much as possible give the 100% of Bitcoin.

But this is probably a case-to-case basis, for a long-term focus on Bitcoin but if you want more risk and high potential of making a profit go for altcoins which is good for a short time investment.  Don't make your money fun and investing in the nonsense altcoin, they aren't worth it to play with.