By Pete Najarian, co-founder of OptionMonsterNEW YORK -- The bulls loved T-Mobile ( TMUS) earlier in the month, and they're looking for the gains to keep on coming. Traders snapped up the August 24 calls for $1.05 on June 14. On Thursday, they sold those contracts for $1.52 and rolled up to the August 26s for 86 cents, with about 11,000 contracts traded at each strike, according to OptionMonster's tracking systems. Long calls lock in the price where the stock can be purchased no matter how far it might rise. They give investors cheap exposure to gains in the shares and can generate some nice leverage in a rally. T-Mobile has been running like a horse since March and rose another 3.85% Thursday to close at $24.55. The call roll allowed the trader to take some money off the table while staying in the game for more upside in the wireless carrier. Total option volume was five times greater than average. Almost 33,000 calls traded in the name versus barely 700 puts, a reflection of the session's bullish sentiment. Najarian owns TMUS calls.