Mark Zuckerberg tried to buy the biggest prediction market in America, and when that failed, he decided to build his own — giving Meta yet another lens into what you think, what you watch, and how you behave.

NPR reports that Zuckerberg met with Kalshi CEO Tarek Mansour last year about a possible takeover as Kalshi's popularity surged. The negotiations never advanced. There are competing explanations: some say Mansour refused to sell, others say Meta found the legal and ethical questions around Kalshi too tangled. Neither company would comment.

Here's why it matters for every American who uses a phone. Prediction markets have exploded from $28 billion in monthly trading volume in June 2025 to nearly $220 billion a year later, according to The Block. Kalshi alone vaulted from a $2 billion valuation to $22 billion in twelve months. That is a staggering concentration of money and attention in one corner of the internet — exactly the kind of shiny object a monopoly-hungry platform like Meta covets.

And when Meta can't buy the market, it replicates it. Zuckerberg has stood up a team building an app called Arena, internal documents show. But there's a catch that should make every free-speech advocate's skin crawl: Arena won't use real money. Users will wager "play money" on outcomes, and Meta's artificial intelligence systems will power the questions and determine who wins and who loses based on whether something happened or not. Let that sink in. An algorithm owned by one of the most censorship-happy companies on earth gets to set the bets and declare the results.

Columbia law professor Tim Wu, who advised the Biden White House on tech policy, told NPR that Meta "seems to clutch at every shiny object" and has been able to "fail again and again without consequence" thanks to its advertising cash cow. He cited the metaverse pullback and the abandoned Libra cryptocurrency project. Wu dismissed Arena as unlikely to thrill anyone: "I can't imagine a casino app with fake money is going to be much of a thrill."

The industry's rapid growth has also drawn heat. State gaming officials insist these sites are gambling by another name, and dozens of legal battles are underway. The Justice Department has opened criminal cases. President Trump has vowed to protect prediction market companies even as insider trading and market manipulation controversies plague the sector.

The pattern is familiar. Big Tech tries to swallow a competitor. When that fails, it clones the product and uses its existing infrastructure — your data, your attention, its AI — to muscle in. If the clone succeeds, another independent platform gets squeezed. If regulators step in, they usually step in on the little guy first.

The open question: who decides what questions Arena asks and what counts as the truth? When Meta's AI is the house, the house always has the edge.