When Ethereum came out, it was looked down upon because the market hadnt matured yet. No one understood much about cryptos beyond the peer to peer transfer. When the difference between Bitcoin and Ethereum was established, that is when we had a surge of the altcoin rush. This caused prices to skyrocket on all altcoins. It seems as if the roles have been reversed and there is more doubt on Bitcoin than anything else. This is why we recommend you hodl Ethereum over Bitcoin.
Source :
https://usethebitcoin.com/will-ethereum-better-investment-bitcoin-2018/It could be posible that ethereum will surpass bitcoin but i think not this year. Yes it is better to hold ethereum over bitcoin because eth is emerging in the market due to ico using ethereum as payments. But bitcoin is still the best when investing in cryptocurrency due to its volume and demand in the market.
It's not bad that ethereum will lift up its current status, and there's no impossible if ethereum will be a next better investment today since ethereum is leveled as a second highest value kind of cryptocurrency today. But of course there's no doubt that bitcoin is still the best kind of cryptocurrency exist.