Maybe because many people have many eth from the bounty campaign or airdrop or eth can be easy to get, like the price is cheaper, so they want eth beat btc to earn many profits from their coins. But in my opinion, it is too hard for eth to beat and win from btc because the price of btc is highest rather than another coins and btc is the king in the cryptocurrency. Eventhough the price of btc decrease, like eth, but it is more stable and valuable.