When investing, Im a big fan of diversification of portfolios. I believe that both Ethereum and Bitcoin offer value, albeit in different ways.
Even though Ethereum is positioning itself to become a large platform, the fact that Bitcoin is so well known makes it the first place where people invest.
Don't choose between the two as these two are promising.
Our coins always fluctuate so we should be used to this. Like when we see it's crashing just calm down and for sure after this there will a sure pump. This is always the trend so better sit and relax. Just hold your eth and btc and wait for the rise and a sure profit.