My guess is that the rise in ETH price is due to big buyer in the market preparing themselves for ICO that runs on the ETH blockchain.

The price dropped because some of the ICO sponsors started to unload the ETH they collected, though some said they were holding until the ETH price climbed again. The cycle will be repeated and in the long run the trend is up and I feel it is the era of blockchain technology and especially for those running on the ETH network.