By David Russell, reporter at OptionMonsterNEW YORK -- Option activity in BMC Software ( BMC) has been active for months, and the bulls came back Wednesday. OptionMonster's tracking programs detected the purchase of about 5,600 June 41 calls for $2.50 to $2.70. Volume was more than 12 times open interest in the strike at the beginning of the day, so these are new positions. The calls lock in the price that investors must pay to buy the underlying stock. They can generate significant leverage if BMC pushes higher. For instance, a gain of less than 10% for the stock will drive up the value of the calls by about 60%. The drawback is that they can also be rendered worthless by just a modest decline in the share price. BMC rose 1.54% to $43.39 Wednesday and is up more than 30% so far this year. Shares gapped higher on May 14 after the corporate-technology company announced that it had rebuffed a hostile takeover and have been holding their ground since then. Calls in the name have frequently appeared on our systems as investors wager on a rally. Overall option volume in the stock Wednesday was triple its daily average, with calls outnumbering puts by 18 to 1. Russell has no positions in BMC.