How one simple mistake lost Matt Damon $600,000,000

Matt Damon has revealed how one simple decision he made back in 2007 has ended up costing him a whopping $600 million.

A video of the actor appearing on stage for a Q&A has surfaced on social media, where Damon shared that he was once offered to play the lead role of Jake Sully in James Cameron’s franchise.

Damon revealed that the offer came in while he was shooting for The Bourne Ultimatum.

Addressing the crowd, he explained: “I was offered a little movie called Avatar. Jim Cameron called me, he offered me 10% of Avatar. You will never meet an actor who turned down more money than me.”

However, Damon said that he knew he’d be needed for more work on The Bourne Ultimatum during post production and so he turned it down.

James Cameron once offered Matt Damon 10% of Avatar if he agreed to star. Damon turned it down.
The film went on to earn $2.7B, with the sequel adding $2.3B.

Cameron later said he might still give Damon a cameo in a future Avatar but the 10% is long gone. pic.twitter.com/latNtZAItD

— cinesthetic. (@TheCinesthetic) January 7, 2026

Recalling the conversation he had with Cameron, he detailed how the director had said to him: “This movie doesn’t need you, it doesn’t need a movie star at all. The movie’s the star, the idea is the star, and it’s gonna work so if you don’t do it, I’m gonna discover some new guy and put him in. But if you do it, I’ll give you 10%.”

Damon recalled how for ‘moral reasons’ he once again turned down the iconic director, to which Cameron was ‘really great about’.

Many people were shocked to discover this information, with one post on X, formerly Twitter, estimating just how much cash Damon missed out on.

It said: “James Cameron once offered Matt Damon 10% of Avatar if he agreed to star. Damon turned it down. The film went on to earn $2.7B, with the sequel adding $2.3B.

“Cameron later said he might still give Damon a cameo in a future Avatar but the 10% is long gone.”

Despite losing out on hundreds of millions of dollars, Damon said the biggest thing he missed out on was the ‘chance to work with’ Cameron.

Many took to the X comment section to share their own reactions, with one user writing: “Matt Damon turning down 10% of Avatar is the ultimate "what if" in Hollywood history, imagine the alternate timeline where he's blue, billionaire, and still Bourne-free. But hey, after Cameron's recent denial, maybe it's all just Pandora's box of tall tales!”

Another said: “Fumbled the half a billy bag.”

And a third person added: “Matt Damon turning down 10% of Avatar is the most expensive “nah, I’m good” in Hollywood history. $500M lesson: always read the fine print when James Cameron calls.”

Although, Cameron has since spoken to the Hollywood Reporter to deny there was ever such deal, so we may never get to the bottom of this.