By David Russell, reporter at OptionMonsterNEW YORK -- Brazilian oil giant Petrobras ( PBR) held its ground Monday, and the bulls are looking for a rally. OptionMonster's monitoring systems detected the purchase of about 16,000 October 24 calls for 14 cents to 18 cents. Volume was more than five times open interest at the strike, indicating that new long positions were initiated. Buying calls locks in the purchase price for the stock, so they can generate some nice leverage in the event of a rally. However, they will expire worthless if the stock doesn't move. Petrobras fell more than 4% early in the session after reporting its first quarterly loss in 13 years. Management later assured investors that costs would ease, causing the shares to close with a 0.54% gain at $20.44. The stock has lost more than one-quarter of its value in the last year amid concerns about the global economy and negativity toward Brazil. In the last two weeks, however, it's been consolidating above its 50-day moving average, which could be leading some chart watchers to believe that it will now rebound. While investors have been aggressively targeting energy names recently, most of those trades have focused on smaller U.S. companies. That makes the Monday's activity especially noteworthy. Overall option volume was quadruple the daily average Monday, with calls outnumbering puts by 3 to 1. Russell has no positions in PBR.