NEW YORK -- Packaging Corp. of America (PKG - Get Report) has been trending higher, and at least one bullish option trader is looking for more gains. 

OptionMonster's Heat Seeker system Thursday detected the purchase of 2,000 April 80 calls for $2.05 and the sale of an equal number of March 80 calls for 70 cents. Volume was below open interest in the nearer-term contracts, which expire at the end of next week, indicating that a bullish position was closed and rolled forward in time. 

Long calls lock in the price where an investor can buy shares, so they appreciate when a rally occurs. Their cheap cost entails less risk than owning shares and creates the opportunity for significant leverage. Money can also be moved from one contract to another to provide more time for shares to rise, as we saw Thursday. 

Packaging Corp. ended the session up 2.6% to $79.58. The containerboard and corrugated-packaging manufacturer appears to be making a higher low than the level where it bottomed after a poor earnings report Jan. 26. The stock also reached an all-time high last month and is above its 100-day moving average. All of those considerations could make chart watchers think that it remains on a bullish trajectory. 

Total option volume in the name was right times greater than average Thursday, with calls outnumbering puts by a bullish 16-to-1 ratio.

-- Written by David Russell of OptionMonster

Russell has no positions in PKG.