Yale Study: 3% of Polymarket Traders Take 27% of the Profits

If you think prediction markets are easy money, the data says otherwise. A new Yale working paper, co-authored with researchers at London Business School, went through two years of Polymarket trades. The sample: 1.72 million accounts and 210,322 markets. The finding: roughly 3% of accounts pulled in 27% of all dollar profits.

Read that again. Three out of every hundred traders are eating more than a quarter of the pie. Everyone else is fighting over scraps.

And here's the thing that should worry you. That edge is already shrinking. The paper points to competition from Wall Street, and that tracks with what I'm seeing. Every few weeks it feels like another prop desk finds a way into prediction markets. They bring faster data, tighter models, and balance sheets that make your $500 bankroll look like pocket change.

So what happens when the pros show up? The same thing that happened to crypto arbitrage in 2018 and NFT flipping in 2022. Spreads compress. The easy alpha disappears. The top 3% becomes the top 1%, and the rest of us are just providing liquidity for smart money.

Real talk: the winners on Polymarket aren't guessing. They're reading news faster than you can open the app. They're pricing in polls, court filings, and Fed minutes before the headline hits your timeline. That's not luck. That's an information edge, and on a platform this small, it's the whole game.

The study doesn't say Polymarket is rigged. It says the platform is growing up. Two years, 210,000 markets, and a profit curve that looks like every other efficient market in history. Winner-take-most isn't a bug. It's what happens when real money walks in.

The chain doesn't lie. Neither does a Yale working paper.

Watch that 27% share going forward. If it keeps dropping, the whales are getting squeezed. If it holds, retail is still the exit liquidity.