Every friend group already runs informal prediction markets. Someone says "no way he shows up before 10," someone else says he will, and suddenly there's a bet nobody wrote down and nobody will agree on how to settle later.

A real prediction market fixes exactly that. It forces the question into a form that can only resolve one way, turns everyone's confidence into a price, and settles the argument instead of extending it.

This guide covers how prediction markets actually work, whether running one with friends is legal, and how to set one up without the group chat descending into a rules dispute.

Quick answer: A prediction market with friends is a bet on a specific yes-or-no question, priced by how likely people think it is, that resolves against an agreed rule instead of a vague memory of who said what. You can run one free with play money or, on a regulated exchange, with real money. folk lets you spin one up from a text and resolves it once the answer's in.

What is a prediction market with friends?

It's the same idea behind a company's internal forecasting pool or an election-odds site, just scaled down to people you know. Instead of trading with strangers, you trade with your group chat on a question your group actually cares about: who wins the fantasy league, whether the flight gets delayed, whether your roommate actually moves out by the deadline.

The price is the useful part. As people buy into "yes" or "no," the price shifts to reflect what the group collectively believes, which is often a better estimate than any one person's gut feeling.

How do prediction markets actually work?

Every market starts as a single yes-or-no question with a deadline and a resolution rule. People then buy shares of "yes" or "no," and the price moves with demand, so a price of 70 percent roughly means the market thinks there's a 70 percent chance of "yes."

When the event happens, the market resolves, the correct side gets paid out (in points or in money, depending on the market), and the price stops moving. The whole mechanism only works if the resolution rule was clear from the start, which is why the question has to be specific.

Are prediction markets with friends legal?

It depends on whether real money is involved. Play-money markets carry no cash value, so they aren't gambling and there's nothing to regulate. Real-money event contracts are legal in the US on a CFTC-regulated exchange, and that market has grown fast: trading volume across CFTC-designated contract markets topped $25 billion in 2025, and the CFTC first designated a prediction market for its oversight back in 2004.

What's murkier is an informal cash side bet between friends outside any regulated platform. That falls under state gambling law, which varies a lot by state. If you want the stakes to be real, the safer path is a licensed exchange rather than a private pool of cash.

Play money vs. real money: which should you use?

For most friend-group bets, play money is the right default. It's free, there's no financial risk, and the only thing on the line is bragging rights, which is honestly the point for most "does Jake show up on time" style bets.

Real money makes sense when you're trading on something like an election or a rate decision through your own account on a regulated exchange, where the contract terms and resolution rules are already defined for you.

How do you create a market for your friend group?

1. Write a question with one clean resolution. "Does the concert start by 8:30?" resolves cleanly. "Is the concert going to be good?" does not.
2. Set the resolution rule and date up front. Agree on what counts as proof and who's the tiebreaker, before anyone has money or pride on the line.
3. Invite the group to trade. Share the market and let people weigh in with their actual read on the odds, not just a yes or no.
4. Resolve it and move on. Once the outcome is clear, close the market so the price stops moving and everyone sees who called it.

How folk runs prediction markets with your friends

folk builds this directly into your group chat, so the market lives where the argument started instead of on a separate app nobody opens.

• Play money by default. folk uses Manifold-style play money out of the box, free and zero risk, so any group can start one immediately.
• Real money if you want it. Connect your own Kalshi account for actual regulated event contracts. Every real-money trade is quote-first: folk shows you the price and asks you to confirm before anything is placed, and hard per-trade and daily caps stop things from getting out of hand.
• Make your own market from a text. Just tell folk the question, like "make a market: does Jake show up before 10pm?" and it creates the market and hands you a link to share.
• It resolves the market. Once the answer's in, folk settles it, so nobody's left arguing about what actually happened.

See markets for the full rundown, or check out markets directly.

The bottom line

Your friend group is already making predictions out loud. A prediction market just gives those predictions a price and a way to actually settle, instead of a debate nobody wins.

Start with play money, keep the question specific, and agree on the resolution rule before anyone bets. If you want it running inside the group chat you already use, get started with folk, the same assistant covered in what an AI can do in your group chat.