Actress Natalie Portman poses with her award for Best Performance by an Actress in a Motion Picture - Drama at the Warner Bros. and InStyle after party after the 68th annual Golden Globe Awards in Beverly Hills, California January 16,2011.[Photo/Agencies]

LOS ANGELES  - A ballet psycho-thriller isn't the typical boxoffice juggernaut, but as Darren Aronofsky's "Black Swan" hit the $75 million mark during the Martin Luther King Jr. holiday weekend, Fox Searchlight received its most detailed breakdown of who is fueling the season's surprise hit:

Women (big surprise!). About 55 percent of the audience is female (17-34 is the sweet spot), and many are bringing their boyfriends and husbands along. Women are giving the film a B+ on CinemaScore; men are a bit less enthusiastic with a B, but that is considered great for a horror/thriller.

People in small cities. After opening in 18 theaters, "Swan" upped its theater count from about 1,550 to 2,328 and extended into smaller communities, turning in top performances in Butte, Mont., Guleph, Ont., Columbus, Ga., Houma, La., and Bangor, Maine. The $13 million-budgeted film is doing especially well in French Canada and heavily Hispanic San Antonio, even though Searchlight initially didn't spend much there.

And big-city types, too. The top-performing theater in the U.S. is the Regal Union Square in New York, where "Swan" will soon become its third-highest grosser of all time, behind only "Avatar" and "Star Wars: Episode I — The Phantom Menace" ($1.7 million each). Other top cities include Boston, Seattle and Chicago.

But not really. L.A.'s Arclight Hollywood is the No. 2 theater overall for "Swan," but Searchlight says the film hasn't overperformed in the broader Los Angeles market.

How high can Swan fly? After her best drama actress win at the Golden Globes, Natalie Portman is a shoo-in for an Oscar nomination, which should send the film past $100 million and possibly toward the ranks of "Juno" ($143.5 million) and "Slumdog Millionaire" ($141.3 million), Searchlight's highest-grossing films. Says Searchlight's Sheila DeLoach, "It has become the movie people have to see."