'Joker' to Become Highest-Grossing R-Rated Film .
The new Warner Bros.
Film is on track to surpass $783 million in global ticket sales.
'Deadpool' earned $783 million worldwide in 2016.
'Joker' has already earned $737.5 million in three weeks through Sunday, Oct.
The film is expected to reach $900 million globally, .
And some experts think it has a shot to hit $1 billion.
'Joker' was directed by Todd Phillips .
And stars Joaquin Phoenix as the supervillain.
'Joker' earned $96 million in its opening weekend, the largest domestic opening of all-time for an October release.