By David Russell, reporter at OptionMonsterNEW YORK -- Traders cleaned up in a hurry in Dish Network ( DISH) on Friday. OptionMonster's tracking systems detected unusual activity on Friday as traders snapped up the September 48.50 calls for 35 cents. There was no open interest in the strike before the options hit, so new money was clearly put to work on the long side. More than 6,500 of the contracts traded by the end of the session. These calls lock in the price where shares can be purchased in the satellite-television company, letting investors cheaply position for a rally and generate leverage. And that's exactly what happened on Friday because those calls doubled to 70 cents as the stock only inched higher. Dish shares closed Friday up 1.62% to $47.72, continuing a nice uptrend in place since April. It's noteworthy that the traders bought September options because they had barely a week to perform before expiring. Sometimes, those are among the best trades uncovered by OptionMonster because such short-term positions force discipline not to overpay and to take the profits when the come. More than 15,500 contracts traded in the session, with calls outnumbering puts by a bullish 8-to-1 ratio. Russell has no positions in DISH.