'Insidious: Chapter 2' keeps box office horror hot

New release "Insidious: Chapter 2" has scared up a surprisingly large box office haul.

The sequel to 2011's "Insidious" brought in roughly $41 million this weekend, making it the second largest September opening ever. (The honor of highest September bow of all time goes to "Hotel Transylvania," and just barely: that 2012 movie opened to $42.5 million last September.)

It's not only a higher bow than industry analysts were expecting, but a more profitable one, too: "Insidious: Chapter 2" was made for just $5 million.

When compared to the original "Insidious," the sequel performed better by leaps and bounds. The first installment opened to $13.3 million in April 2011, and went on to make $54 million domestically.

Both films star Patrick Wilson and Rose Byrne in a family that seems to be a magnet for evil spirits, and while critics haven't adored either installment, audiences apparently have.

Then again, horror has been the mainstay challenger this year. As the Wall Street Journal reports, the genre is "having a banner year" at the box office, beginning with Andrés Muschietti's January release "Mama" making $71.6 million stateside on a budget of $15 million.

With the "Insidious" sequel performing very well - likely helped by its Friday the 13th release date and the first film's strong reputation - horror movies have become "the closest thing today to a safe box office bet."

Robert De Niro's mafia comedy with Michelle Pfeiffer wasn't as secure. "The Family," which starred De Niro as a mob honcho who has to relocate his family to France under witness protection, earned $14.5 million in its first weekend.

It was followed by Vin Diesel's "Riddick," which earned $7 million; "The Butler," which brought in $5.6 million; and the Jennifer Aniston and Jason Sudeikis comedy "We're The Millers," which earned $5.4 million.