My guess is eth. BTC is taking a big hit as we speak...
I'm sure this year is still for Bitcoin. And I firmly believe that in 2018 this is the permanent King of Bitcoin and Ethereum cannot replace that position. It may take several more years for Ethereum to be like Bitcoin.
We can see that bitcoin marketcap is still the largest of all cryptocurrencies. as well as the volumes of money that are circulating in the bitcoin market each day. it proves that bitcoin is their main coin for users. Ethereum itself occupies second position for the largest marketcap. but despite so many people investing in other altcoins. still they will definitely use bitcoin as their reference