That was pretty expected that before Constantinople hardfork we will drop or straight after, but we did before, a large number of longs been on the market. In the long term, especially if we will see 500 transactions per second have great chances of ETH go way higher.
I think it is only a coincidence that this fall in the price of Ethereum took place just before Constantinople hardfork.
I know that there have been such situations in the past, but it disturbed price only coins, that were supposed to have hardfork, not the entire cryptocurrency market. I think this is the further effects of the bear market.