Warner Bros. Harry Potter film series was the worldwide highest-grossing film series of all time without adjusting for inflation. Its Batman film series was one of only two series to have two entries earn more than $1 billion worldwide. Harry Potter and the Deathly Hallows – Part 2 was Warner Bros.’ highest-grossing movie ever (surpassing The Dark Knight). However, the Harry Potter movies have produced a net loss due to Hollywood accounting. IMAX Corp. signed with Warner Bros. Pictures in April 2010 to release as many as 20 giant-format films through 2013.