Why Marvel Trailers Keep Leaking — And Who’s Really Benefiting
Marvel’s rollout just sprang a leak: over the past week, trailers for Avengers: Doomsday and Spider-Man: Brand New Day spilled online, igniting a social media frenzy. What’s fueling the surge—and how fast can the studio slam the door on it?
Marvel tried to play keep-away. Fans grabbed the ball anyway. The first of four teaser trailers for 'Avengers: Doomsday' is running exclusively in theaters with 'Avatar: Fire and Ash', and it did not stay exclusive for long. That teaser leaked online earlier this week (complete with a surprise returning face), then audio from a second 'Doomsday' teaser appeared, and then the big one: the full trailer for 'Spider-Man: Brand New Day' spilled out too. Marvel usually guards this stuff like the nuclear codes (Tom Holland jokes aside), so yeah, something is up.
So why all the leaks?
One working theory, at least for the 'Brand New Day' trailer, comes via THR's Heat Vision newsletter. They point to a not-very-sexy but very plausible weak link: the market-research portals studios use to test trailers with regular viewers under NDA.
'It escaped from a service studios use to get early feedback on trailers from average moviegoers, who sign NDAs in exchange for looking at stuff early... The Brand New Day trailer is played on a computer screen that could be logged into such a site, but it’s unclear.'
Translation: someone with access to a passworded feedback site probably hit record. The detail about the trailer playing on a logged-in computer tracks with that, though it is not confirmed.
When will the 'Brand New Day' teaser officially drop?
There are rumors, but nothing locked. One version has the teaser attached to 'Anaconda' on Christmas Day. Another says it could surface during the Super Bowl in February. Marvel has not confirmed either plan.
What 'Brand New Day' actually is (and who is in it)
Production just wrapped on 'Spider-Man: Brand New Day'. Destin Daniel Cretton ('Shang-Chi and the Legend of the Ten Rings') directed from a script by Chris McKenna and Erik Sommers. Tom Holland is back as Peter Parker, and the supporting roster is stacked with both familiar faces and a few wild cards. Sadie Sink is in the mix in a mystery role, and reports suggest she is also set for 'Avengers: Secret Wars'. Two notable names, Liza Colon-Zayas and Tramell Tillman, are on board in undisclosed roles.
- Tom Holland as Peter Parker/Spider-Man
- Zendaya as MJ
- Jacob Batalon as Ned Leeds
- Jon Bernthal as Frank Castle/Punisher
- Mark Ruffalo as Bruce Banner/Hulk
- Michael Mando as Mac Gargan/Scorpion
- Marvin Jones III as Lonnie Lincoln/Tombstone
- Sadie Sink in a secret role
- Liza Colon-Zayas and Tramell Tillman in unspecified roles
The release calendar
'Spider-Man: Brand New Day' hits theaters July 31, 2026. 'Avengers: Doomsday' follows on December 18, 2026.
The bottom line
In the span of a few days, we got a theater-only 'Doomsday' teaser that still leaked, audio from its next teaser, and a full 'Brand New Day' trailer floating around the web. If the research-portal theory is right, the leak did not come from some elaborate heist so much as a boring login screen and a screen-capture app. Either way, expect Marvel to tighten the screws. And if you care about seeing these things as intended, maybe avoid your timeline for a minute.