1. Bitcoin is _very_ thinly traded. I'm speaking as someone who sold at $1100 and bought back in at $450, which at the time was very near the bottom. In a matter of seconds, the price was $500. In those precious seconds, I'd be shocked if more than 10000 BTC traded hands. That's barely enough room for a handful of traders to call the bottom. Like I said, very, very thinly traded.

2. I would never do the above, ever again. Speaking as an American citizen, there's no good domestic exchange. If you're dealing in amounts above $10,000 say hello to the FBAR. The BSA's online efiling site isn't quite as bad as healthcare.gov, but JFC. Ultimately you have to use IE on Windows, load a PDF through IE's Acrobat extension, and then fill out the form inside IE. You then have to sign the form with your given PIN, which execs some JavaScript if I remember correctly. Obviously the FBAR form isn't fun. I picked up a few more coins but at the cost of having to disclose all of my financials to the BSA, and I'm just praying that I did things correctly. On top of that, taxes. YMMV, but IMO it's not worth the hassle to sell.