it usually makes sense
Bitcoin isn't usual.
All it takes is one mistake when it moves against you and you've permanently ended up with half the BTC you could have owned if you'd have just held.
It would have made sense two out of the three "bubbles" to do so. This price will crash as well. I am taking profit when it looks like the top and I'll double or tripple my coins on the buy-back.
good luck with that
What is luck about it? If you sold at $250 and bought back at $100 you would have done just as well. If you did the same at $30 even better. Once this rise is done its going back down to $400-$500. You sell once it starts going parabolic and buy in. Its not that difficult. Only thing is this past bubble burst early, so get back in to make profit and let it burst again.