Sadie Sink reveals fans got one theory right

It is not uncommon for fans to speculate about a project online. But there are times their theories hit the spot. Sadie Sink reveals one of them.

Appearing on The Tonight Show Starring Jimmy Fallon, she says fans on the internet were correct to predict her casting in Spider-Man: Brand New Day.

“There’s so much speculation too, I feel like there’s a new character every week,” she acknowledges, adding, “I tell people, like the people I know."

However, she adds that the fans correctly predict a theory about her casting. 

"But I found out through online theories. Before I got cast in Spider-Man, there was speculation online that said, ‘Sadie Sink is going to be in the new Spider-Man. I was like, ‘Hmm? I am?’ And sure enough, two days later, they asked me to do it."

“So yeah, those theories, there’s sometimes some truth to it," the Stranger Things star notes. But there is another theory that centres on Sadie's character in the upcoming Spider-Man film, which, she suggests, fans do not get right.

That is, she is playing Jean Grey, an X-Men character in the movie. “That was happening before I even knew that I would be working on this project,” she told Entertainment Weekly. “I was like, ‘Wait! What are people talking about?”

She picked holes in the theory by pointing out, “A lot of people forget that hair colour can change, but yeah, I understand all of the theories,” she said. “People will just have to wait and see. I am excited for all of it to maybe be put to rest.”

Apart from these theories, Sadie's character in the new Spider-Man film has been kept under wraps. Brand New Day debuts globally in theatres on 31 July 2026.