It happens sometimes even without any major PRs. It just takes the right buyer and seller hitting the board at the same time, especially on a slow paces, low volume day or intraday period. As long as somebody throws an ask price up that's say 10% or more above the current price or previous close, and no one throws a lower ask up there, all that needs to happen then is someone deciding they're willing to buy at that price or market if they can and up it goes 10%. For a lot of longs, little fluctuations in price at low prices doesn't always deter them from buying since they have a strong belief that the price will be moving WAY up from current levels. Looking at it as most day traders would it seems illogical.