Bitcoin is an asset class commodity that will rise several fold within the next few years.
With Ethereum it is an open software platform based on the blockchain technology that allows developers to building decentralized applications -DAPPS. So, not only is it an asset class it has other functions, mainly to run DAPPS.
With that said, I could see Ethereuem, and other DAPP blockchains, rising faster percentage wise than Bitcoin.
You could see Ethereuem even surpass Bitcoin price wise in the near future!