Film stocks plummeted today following the announcement that Warner Bros. will release its entire 2021 film catalog simultaneously in theaters and on HBO Max.

According to Variety, Cinemark fell more than 21 percent, while the Marcus Corporation dropped more than 11 percent. Imax also took a hit, sliding more than 7.3 percent. AMC Theatres, whose stock was already falling today after it announced it was selling 200 million shares in an effort to raise $844 million, took a dive as well, falling more than 17 percent. National Cinemedia, which is responsible for the pre-show advertising on movie theater screens, took a 6.8 percent hit.

RELATED: Warner Bros. Boss Explains Simultaneous HBO Max/Theatrical Releases

Theaters were already facing dire circumstances thanks to the coronavirus (COVID-19) pandemic. Nearly the entire summer movie schedule was delayed or moved to streaming/VOD, with only Tenet and The New Mutants releasing in theaters at the tail end of the season. The HBO Max decision is bound to cut into revenues for theaters that were hoping to get a boost in 2021 from major films like The Suicide Squad, Matrix 4 and Dune.

The slate will begin with Wonder Woman 1984which will premiere in theaters and on HBO Max on Dec. 25. The theatrical films will leave the streaming service after a month, and will only be available in domestic and international theaters from then on. After the theatrical window closes, the movies will gradually return to streaming and make their way to VOD.

RELATED: HBO Max's Wonder Woman 1984 Could Help Warner Bros. Reintroduce the DCEU

"We believe economically first and most importantly, it's the right thing to do for fans, it's the right thing to do for exhibition, and the right thing to do for talent, considering the circumstances," WarnerMedia CEO Jason Kilar said while explaining the groundbreaking decision. "With that in mind, we believe that what we announced today is going to optimize the economics. And the reason why is twofold: The revenues that are generated by the box office, of course, and the other is the value of the consumption on HBO Max from existing subscribers and what we anticipate to be more subscribers coming into HBO Max who choose to do so because of the presence of these films."

The full HBO Max 2021 movie lineup includes The Little Things, Judas and the Black Messiah, Tom & Jerry, Godzilla vs. Kong, Mortal Kombat, Those Who Wish Me Dead, The Conjuring: The Devil Made Me Do It, In The Heights, Space Jam: A New Legacy, The Suicide Squad, Reminiscence, Malignant, Dune, The Many Saints of Newark, King Richard, Cry Macho and Matrix 4.

KEEP READING: HBO Max to Spotlight Holiday Favorites in 200-Hour Collection

Source: Variety