Bitcoin prices have never been so low this year. Prices were down to 5,826.41$ (Jun 24 2018 16:04:00 UTC). Many advisers say that at the end of the year it will hit 30,000$. The market is seeing more than the fall from the price rise. Imagine when the speculation will end?
In my own opinion, decreasing of prices today is just normal because the value of bitcoins last december has pumped so hard so it is normal for the price to go down this days.