It's not an unusual rise for this company, it does it about once...

It's not an unusual rise for this company, it does it about once a year, plus numerous rises of 10-20% in a day. Last year's 20% rise was a breakout that led to a the price more than doubling in around 5 weeks. As to why it happens, I'm not sure, but on both occasions drilling results were released a couple of weeks earlier, so it may be a delayed reaction to that. A broker or tip sheet writer will read the drilling report, make a favorable recommendation, and the thing snowballs.