I think this is just normal of Bitcoin. The other week bitcoin was at this price then it goes up and goes back to this price again. This is what we called high volatility. Wild fluctuation that attracted lots of day traders since they can book big profit from this price changes. I am surprised that OP is still surprise about this kind of price changes in Bitcoin. And about ETH it goes down because it should since ETH had form a bubble and seems this bubble burst.
Exactly! It may seem shocking at first but we also need to understand that BTC is becoming popular everyday. The market may crash anytime soon but this does not mean that its value will completely change. These changes of its price fluctuates every now and then due to other factors determining its price. I also do think that this is a good time to buy one for investment because of its low price in the market.