By David Russell, reporter at OptionMonsterNEW YORK -- The bulls are piling into Fortress Investment ( FIG) as two big events loom on its calendar. OptionMonster's tracking systems detected the purchase of more than 2,000 March 6 calls, most of which priced for $2.25. Volume was more than 100 times open interest at the strike, indicating that new positions were initiated. Calls lock in the price where shares can be purchased in the investment company. Investors use the contracts to position for upside cheaply, to limit capital at risk, and to generate leverage. Fortress rose 0.25% to $7.99% Tuesday and has more than doubled in the last year. It's been tracking the performance of Nationstar Mortgage ( NSM), its largest investment, which also saw bullish call buying Tuesday. Both companies will report earnings in the next week: Fortress on Thursday, and Nationstar next Tuesday. Total option volume was eight times greater than average in the name Tuesday, with calls outnumbering puts by a bullish 5-to-1 ratio. Russell has no positions in FIG.