NEW YORK -- The bulls are chasing Walgreen Boots Alliance (WBA) - Get Report as the pharmacy stock rips to new highs. 

OptionMonster's Heat Seeker system detected the purchase of 16,000 March 80 calls Wednesday, most of which priced for $1.25. The volume was more than 18 times the previous open interest in the strike, which indicates that new money was put to work. 

Long calls lock in the price where investors can buy a stock, allowing them to profit from a rally at limited cost. The contracts help manage risk and can produce significant leverage if the stock moves higher. 

WBA rose 3.7% to $79.53 on Wednesday and is up about 30% since October. It's been climbing as Chicago-based Walgreen, the largest U.S. drugstore chain, completes its purchase of European pharmacy giant Boots Alliance. Shares were stuck at last year's peak around $77 before Wednesday's breakout. 

Overall option volume in the name was seven times greater than average in the session, with calls accounting for a bullish 81% of the total. 

-- Written by David Russell of OptionMonster

Russell has no positions in WBA