By Pete Najarian, co-founder of OptionMonsterNEW YORK -- The bulls got off to a quick start in Ultra Petroleum ( UPL) on Friday morning. OptionMonster's tracking systems detected the purchase of more than 6,000 September 26 calls against previous positioning of 2,473 contracts. The first blocks priced for 25 cents shortly after the open, followed by continued buying throughout the session. Calls lock in the price investors must pay to buy shares in the independent energy company, which is primarily focused on developing areas in the Green River Basin of southwest Wyoming. Those options could generate some nice leverage if the stock rallies, but they will expire worthless if it doesn't. Ultra Petroleum declined 1.01% to $22.62 on Friday. Energy has been a theme for awhile and continues to a sector in focus for unusual activity despite slowing down a little in the last week. Option volume in the name was almost twice the daily average. There were more than 9,500 total calls, versus barely 2,000 puts, so it was definitely a bullish session. Najarian owns UPL calls.