The Marvel superhero pic tumbled 66 percent in its sophomore outing domestically, compared to a 53 percent drop for DC's 'Superman.'

Those are the worst examples of weekend-to-weekend collapses by MCU titles in the post- Avengers: Endgame era, and Fantastic Four: First Steps didn't perform THAT badly in the last three days... but the results are definitely disappointing.

Marvel’s First Family might not save the day after all. “The Fantastic Four: First Steps” is quickly losing steam in its second weekend, signaling the comic book adventure isn’t connecting at the box office beyond the film’s core demographic of superhero fans.