Celebrity look-alike contests have become a summer staple. But this one was singular: The most convincing Jalen Brunson doppelgänger would win $5,000.
After the audience at Washington Square Park on Wednesday crowned a winner — a 5-year-old from Jamaica, Queens, who resembled a mini version of the star Knicks point guard — the young champ turned to a camera and addressed an unusual entity.
“Thank you, Polymarket!” the boy, Fransisco Marcial, said.
Polymarket, one of the biggest prediction markets in the United States, bankrolled the contest. It was another reminder of the ubiquity of the industry, which was on display across New York City during the N.B.A. finals.
Prediction market platforms paid influencers who concocted pro-Knicks catchphrases and pulled viral social media stunts. The companies promoted themselves on TikTok and worked with at least one Upper East Side bar to cover everyone’s tab after the Knicks had rallied to beat the Spurs in Game 1.
At Madison Square Garden, a sixth-floor concourse was renamed after Kalshi, Polymarket’s main rival. Outside the arena, a robot danced in a Kalshi-branded Knicks jersey, and a billboard beamed: “Will New York bring it home? Trade now on Kalshi.”
Then there were the bets. In addition to betting on who would win, you could wager on whether President Trump would attend Game 3 of the finals (he did) and whether Mayor Zohran Mamdani would cancel classes for Thursday’s ticker-tape parade (he did not).
“It’s a perfect storm of things Americans love,” said Timothy W. Fong, a director of the gambling studies program at the University of California, Los Angeles. “Sports, a story for the ages, making money fast and really creative games that draw people’s attention.”
Kalshi declined to comment on Thursday. Polymarket did not return a request for comment.
Prediction markets have exploded as a popular front for Americans to bet on everything from a Knicks victory to the ousting of foreign leaders. Billions of dollars are traded on Kalshi and Polymarket each month, and the markets have entered into partnerships with sports leagues and major media companies.
The companies are bringing on stars like Timothée Chalamet to promote their brands and expand their audience. Yet the platforms’ prevalence has created risks, which dovetail with broader concerns about the effects of widespread gambling.
Younger Americans, particularly men, are gambling — and losing money — at high rates. And there are growing fears of insider trading and market manipulation on the platforms.
Michael Robb, head of research at Common Sense Media, a nonprofit watchdog group,said he worries that “the line between investing and entertainment, and being a fan and gambling” is being blurred — especially for young people, who seem to be a ripe audience for Kalshi and Polymarket’s messaging.
“There’s this big cultural moment that a kid and all his buddies might be really into,” Dr. Robb said. “There’s a lot of social media hype — and there’s a reservoir of young male fandom that they can tap into.”
As New Yorkers celebrate a championship 53 years in the making, the omnipresence of prediction markets has at times emerged as a sore subject. “Kalshi is hijacking the Knicks watch parties to manufacture viral moments for advertising,” a recent social media post from Josh Billinson, a social media editor at the news start-up Semafor, lamented.
Experts see plenty more opportunities for prediction markets to seize during a busy summer that includes the World Cup, celebrations for the nation’s 250th anniversary and potentially even Taylor Swift’s wedding, which reports speculate may be held in Manhattan.
Jonathan D. Cohen, who leads gambling policy at the American Institute for Boys and Men, a research institute, said that prediction markets appeared to be riding the coattails of Knicks mania. He said they had appropriated the playbook of big names in traditional sports betting, where the “genie got out of the bottle really fast.”
“They want you to learn about them from Giannis Antetokounmpo or a dancing robot at a Knicks party because it looks sick,” Mr. Cohen said. “You hunt where the ducks are. And right now, the ducks are partying over the Knicks.”
The future of prediction markets is uncertain, said Eric Zitzewitz, a professor of economics at Dartmouth College who has studied the industry. How the companies might fare under a less friendly presidential administration remains an open question, he said.
“If this industry may turn to dust in 2029,” he said, “their incentive is to make as much money as they can” until then.
Kalshi and Polymarket are also in “a race to become the predominant player” in a space that tends toward monopoly, Mr. Zitzewitz said. Where one woos users, the other must be.
Jake Epstein, 22, organized Wednesday’s look-alike contest. He recently livestreamed outside Madison Square Garden saying “Jalen Brunson” 100,000 times, and said a Polymarket representative had contacted him even before the stunt, which had captured online attention and in-person crowds, was over.
“They reached out to me during the video and said, ‘We want to do another one,’” said Mr. Epstein, who came up with an idea for a video to “support someone who was down and out with rent.”
On Wednesday, Mr. Epstein, clad in a cobalt blue Polymarket sweatshirt, hyped up the crowd — several dozen strong — in Washington Square Park.
“Can I get a ‘Go New York, go New York, go’?” he called out, invoking the Knicks’ anthem. (The crowd roared the words back.)
Armed with a microphone plastered with the Polymarket logo, Mr. Epstein opened Zelle to wire money provided by the prediction market to the young winner’s mother.
Onlookers were captivated. The real Jalen Brunson briefly joined a FaceTime call to congratulate “little Jalen” — even if the fine details escaped some attendees.
“Oh, it’s Polymarket!” one young man in the crowd said midway through the contest. “That’s a YouTube channel.”
“Is that not like a betting thing?” a woman with him chimed in.
“Oh yeah,” he replied.
