Today, Iron Man 3 will become the first film of 2013 to cross $400 million at the U.S. box office. Iron Man 3 finished Father's Day weekend with $399.6 million at the U.S. box office, and the film has been averaging over $600K per day on weekdays. In crossing the $400 million threshold, Iron Man 3 will become just the 17th film in the history of the domestic box office to accomplish such a feat. Iron Man 3 will also be the fifth superhero movie to reach $400 million in the U.S., joining The Avengers, The Dark Knight, The Dark Knight Rises, and Spider-Man. Making Iron Man 3' accomplishment even more impressive is the fact that no other movie has even reached $300 million at the domestic box office in 2013. The next closest challenger to Iron Man 3 is Oz The Great and Powerful, which sits over $165 million behind Iron Man 3. Will Iron Man 3 finish 2013 as the highest grossing movie of the year? There are relatively few blockbuster films left that could challenge Iron Man 3. Man Of Steel could have a chance if it has a long box office run, and The Hunger Games: Catching Fire could make a run when its released in November. However, odds are Marvel Studios will have the highest grossing movie of the year for the second year in a row.