Pearl Jam lead singer Eddie Vedder was moved to tears at a recent concert at the MGM Grand Garden Arena in Las Vegas after a fan made good on a bet he entrusted her with.

Vedder staked a member of the audience with a wad of cash

At a May 16 concert in Las Vegas, Eddie Vedder staked a member of the audience with a wad of cash, telling her any proceeds would go to the frontman’s charity, the EB Research Partnership. The organization aims to find a cure for Epidermolysis Bullosa, a genetic disorder in which a person lacks proteins that bind the skin together. “Without these proteins,” the charity’s website says, “the skin tears apart, blisters, and shears off, leading to severe pain, disfigurement, and internal and external wounds that may never heal.”

“Here’s $500, just see if you can double it, I trust you,” Vedder told the audience member, who media identified only by her first name, Erin.

“If you lose it all, it was part of the experiment, and if you win any of it, we split it,” Vedder said.

Vedder asked Erin for the results of her bet at a later Pearl Jam concert in Las Vegas. Erin handed Vedder a letter she wrote and the singer read out aloud to the 17,000+ crowd.

“Ed, I stayed up all night but in the end, the casino had the upper hand,” Vedder quoted.

Yet when Vedder looked in the envelope, it contained $1,500 in cash.

“Holy fucking shit,” Vedder exclaimed. “Well that I did not expect. We’re so thankful, the whole EB community thanks you,” he said, wiping tears from his eyes.

Vedder passed the money to his wife Jill, with whom the singer formed with charity in tribute to a close friend with a “rare and sometimes fatal skin disorder,” and teased her to “try and double it.”