By David Russell, reporter at OptionMonsterNEW YORK -- The casino bulls targeted Boyd Gaming ( BYD) Wednesday, barely a week after Pete Najarian hit the jackpot in Caesars Entertainment ( CZR). optionMONSTER's monitoring program detected the purchase of almost 5,000 April 8 calls against open interest of 3,282 contracts. Buyers initially paid 45 cents to 55 cents, but then Boyd advanced and the premiums climbed as high as 86 cents. Calls lock in the price where investors can buy shares, so they can generate significant leverage from even a modest move in the underlying stock price. They can also predict direction because they reveal the intentions of big-money players. That's exactly what happened Wednesday. Boyd was up barely 1% when we first flagged the activity, and then surged more than 8% before pulling back. It closed at $8.66, a gain of 5.74%. The stock has been running higher in the last month, propelled by hefty short interest and a surge of bullish activity in the casino industry. Total option volume was almost five times greater than average in BYD Wednesday, with calls accounting for more than three-quarters of the total. Najarian cited unusual activity in Caesars earlier this month as investors bought the April 20 calls. The stock kept powering higher after his alert and those contracts more than doubled in value. Russell has no positions in Boyd.