People invest in Bitcoin so that they could have safety while they are earning money. And op, if you are holding your Bitcoin then you can see that how it growing from then to now, almost 4x in my analysis. And here is the fact that, bitcoin won't give you x10 or more, like altcoins. That's why it's comes altcoins investment in mind. And i think it could be an another opportunity to earn more if yousell some percentage of Bitcoin and holding some top leading altcoins, what are trusted and could give you decent amount of money besides bitcoin.
Then what would be the intention why OP is asking here about Idea in diversified portfolio but with altcoins maybe he already had Bitcoin in his pocket and just wanted to have extension from his target profit in the coming bull market as we are heading to this in the coming months of if not in the year more.
bitcoin will gop first and then altcoins will comes next.