Disney and Marvel Studios' The Avengers is expected to cross the $800 million mark Thursday, putting it on course to hit $1 billion in global grosses by Sunday or early next week.
Only James Cameron's Avatar has reached $1 billion so quickly. Avatar, released in December 2009, hit the milestone in 17 days; Sunday will be Avengers' 17th day in release.
Through Wednesday, the superhero tentpole directed by Joss Whedon had grossed $775.4 million worldwide, including a Wednesday take of $31.2 million. Last weekend, it scored the biggest domestic debut of all time with $207.4 million.
This weekend, Avengers has a strong shot at grossing $100 million domestically and $100 million overseas. But those numbers could come in lower if the drop is bigger than expected.
The only new wide release of the weekend is Tim Burton's campy adaptation of the 1966-71 daytime soap Dark Shadows, which begins rolling out at midnight Thursday in the U.S.
The Warner Bros. pic, headlining Johnny Depp as a vampire, is tracking to open in the $35 million to $40 million range domestically. It also opens in 42 markets overseas, where Depp is a huge international star.
Dark Shadows could beat Avengers in certain territories but might not be able to match Avengers' overall weekend international gross. Burton's film got off to a strong start Wednesday in France, grossing north of $750,000.
Produced for $100 million, Dark Shadows is tracking best among women, though interest has picked up among men in recent days. The film also stars Michelle Pfeiffer, Helena Bonham Carter, Eva Green and Chloe Grace Moretz.
Warners believes the film will have strong legs, since the other May tentpoles are more male-driven, including Universal's Battleship, which opens May 18.