Yep!
It's like a rollercoaster ride, and I'm having a lot of fun with it.
Selling the peaks and buying the dips has so far paid for the two modest rigs (each w/2xR9-380x) I built to mine ETH, and in addition to what I keep on the exchange to play around with in this way, I still hold 'some' in reserve locally for a longer position
I didn't start out with more than I was prepared to lose, in the first place... so I'll likely either end up "very happy" or "not too upset" in the end.