When Timothée Chalamet posted a cryptic one-word caption on social media recently, simply reading “Kalshi,” it marked a turning point for prediction markets. An A-list actor with massive cultural currency had just aligned himself with a platform that, not long ago, was scraping for partnerships with fringe political influencers.
So how did we get here?
Kalshi was founded by Tarek Mansour, a former Goldman Sachs trader who had an “aha moment” in 2016 when investors kept calling his desk asking how to bet directly on a presidential election outcome.
There was no clean way to do it.
After leaving Goldman, Mansour tried to build one, calling 50 lawyers before finding a single one willing to take the idea seriously. By 2018, Kalshi was a company, though it spent years grinding through intense regulatory resistance from the Commodity Futures Trading Commission.
The political winds shifted everything. In September 2024, a court ruling allowed Kalshi to list election markets, pulling it into mainstream political coverage.
When the platform’s odds favored Donald Trump before most media organizations were willing to say so, it endeared Kalshi to MAGA circles and helped legitimize prediction markets as a political information source.
Donald Trump Jr. eventually invested $10 million into competitor Polymarket and became an adviser to both companies. Under the second Trump administration, the regulatory environment opened further, and Kalshi began listing markets on virtually anything imaginable, from war outcomes to what words a president might say in a speech.
The strategy to become a cultural institution has been deliberate and layered. Bobby Allen, NPR’s leading reporter on prediction markets, identifies three main engines.
First, in states where sports betting remains illegal, Kalshi stepped in as a legal alternative, with a lower age requirement of 18 versus the standard 21.
Second, the company aggressively recruited influencers across TikTok, Instagram, and X with affiliate deals, flooding social feeds with branded content, some of it undisclosed and some containing outright falsehoods.
Third, Kalshi identified its most compelling users, people who claimed to have paid off student loans or saved for a home through the platform, and had its PR team, stacked with former Meta employees, push those stories to major media outlets.
That media normalization is arguably what made the Chalamet partnership possible. As Allen put it, “These prediction market companies are partnering with CNN, the Wall Street Journal, the Associated Press. Awards shows now increasingly have prediction market odds built into the programming.”
Once those institutional endorsements were in place, the social cost for a celebrity to partner with Kalshi dropped considerably. As Allen bluntly noted, “Everyone has a price.”
The darker side of all this is harder to ignore. Critics point to markets on California wildfires and military strikes overseas, raising real questions about who benefits from those bets going the right way. Insider trading is a persistent concern.
Kalshi made headlines by going after a Mr. Beast video editor who traded on content he was editing, but experts in the field say that case was minor compared to what likely goes undetected.
Legally, the whole enterprise rests on what Allen describes as “a giant loophole in the law” that went unexploited until the current administration. Dozens of lawsuits from state governments and tribal gambling interests are working their way through federal courts, and a Supreme Court ruling could force both Kalshi and Polymarket offshore overnight.
For now, though, the Chalamet ad exists. And Kalshi makes one to two percent on every trade it facilitates. All attention, it turns out, really is good attention.
