I will vote for bitcoin if your aiming to hold until the next year. Depends on your capital, divide your investment into 50:50 maybe better as you may get double profits from both of it. Ethereum price has been dropped back right now and you may buy a lot of it, on the other hand bitcoin price at ATH right now, higher price and be careful of crash, I suggest to buy bitcoin in the dip, maybe $800-$900 if ETF get disapprove.