About the rally itself: I kinda feel that this was orchestrated by a single entity, probably in order to induce a short squeeze. I doubt very much that this was "organic" buying by people who suddenly all decided to buy in unison. Or maybe I'm wrong and it was caused by a bunch of people buying because of the paypal news, but I doubt it...
I followed the rally early on and decided @ about $415 that someone was trying to squeeze those 11000 shorts out. So I went "picking up pennies in front of the steamroller" - I bought into the askwalls, then set up my own askwalls at a slighty higher price. Worked out well, but I would have been in trouble if the price had reversed suddenly. Bids were very thin, so I wouldn't have been able to sell the coins back at the price I bought them at. Was probably not a good idea, even though I made some profit.
Similar to my own ideas: I don't think it was "organic" either, in the sense of buying pressure slowly building up, then being released. Looked like a single entity to me as well, only question is: why? Seems by buying gradually, you could minimize slippage, so assuming the original assumption (one entity driving this one) is right, I can see two reasons to buy it all at once, across exchanges: to "make a point" for the bulls, or to squeeze shorts. The latter didn't seem to work (so far), however, judging by the finex stats.
I will tell you why. Now we will stay in this range for some time so the whales can distribute more coins to some bulls thinking we gonna go above 450$ and stay there (which would mean breaking downtrend that was going for months). This is very bad because price will still go down after all but we gonna have another level of resistance later on on the way up. F*ck you whales, could have dumped some more to retest previous lows first and then rebound with this news.