By Pete Najarian, co-founder of OptionMonsterNEW YORK -- Options activity was huge in MGM Resorts ( MGM) on Thursday, and fast money was the name of the game. The Weekly 11 calls expiring today really stood out on OptionMonster's tracking systems, with buyers snapping up contracts early for 5 cents. The stock eased off the highs of the month, and we shot out an alert with the calls going for 4 cents. But then buyers returned and inflated the premiums into the close, more than doubling them to 12 cents. Calls lock in the price where investors buy a stock, and when they're short-term contracts such as weeklies they can really move in a hurry. The leverage can be extreme when the timing is right, but the clock is ticking on those options, so they can go to zero if the stock doesn't rally above their $11 strike price quickly. MGM ended Thursday's session up 10% at $10.97. More than 91,000 contracts traded, compared with about 12,000 in a typical session. Calls outnumbered puts by 5 to 1, a reflection of the day's bullish sentiment. Najarian has no positions in MGM.