How to spot an information leak on Polymarket: when the odds move before the news
A leak on a prediction market looks like a sharp jump in the odds of an unlikely outcome with no public news, driven by one or a few new accounts with large bets. You can watch for it with the market's activity tab and a wallet explorer, but treat it as a signal to investigate, not a reason to follow blindly.
The cases that made this a topic
Nobel Peace Prize, October 2025. María Corina Machado's odds on Polymarket rose from a few percent to above 70% in the hours before the announcement in Oslo. Reporting by Bloomberg and others traced much of the buying to a few accounts, including one created that month with no earlier bets. Norwegian officials opened an inquiry into a possible leak.
Venezuela, January 2026. Markets on Nicolás Maduro leaving power moved before the public announcement that he was in US custody, and one account reportedly made several hundred thousand dollars.
Prediction market trader Domer documented more cases on X, including a market where the price started climbing about 12 hours before a military strike, and analyst Alex Krüger pointed to a spike in the odds of a Fed chair nomination the day before the announcement.
Show as table
| Value | Note | |
|---|---|---|
| Before the overnight buying | 3.6% | the day before the announcement |
| Hours before the announcement | 70% | after a few accounts bought heavily |
What a leak looks like on the screen
- An unlikely outcome moves fast with no news. A jump from single digits to 30%+ within hours, while news sites and X have nothing new.
- The buying comes from few accounts. Open the market's activity or "top holders" tab. Leaks are usually a handful of large buys, not hundreds of small ones.
- The accounts are new or single-purpose. A wallet created days ago that only ever bet on this market is the classic pattern. Check the wallet on Polygonscan: when was it funded and from where?
- Timing fits a decision that is already made. Prize committees, court rulings and military operations are decided before they are announced. That gap is where leaks happen.
What to do with it
A move like this is information, but not proof. Sometimes the "insider" is a fan with a big wallet, as with a Polymarket user who kept buying a celebrity outcome against all odds. Before you follow a move, ask what decision is already made, who could know, and how much is left to win if you buy at the new price. Buying at 70 cents to win 30 is a very different bet from the insider's 4 cents.
The same signal is useful in the other direction. MemeSonar's event calendar reads Polymarket because large money moving on an event often comes before tokens named after that event start to move. A sudden odds shift on an event in the calendar is a reason to look at those tokens, and at their rug risk, before the crowd does.
Also read: how to read Polymarket rules before you bet.
MemeSonar does this for you in real time: every new Solana token, every influencer call and every tracked wallet, scored and filtered for rugs.
Request accessNot financial advice. Numbers are measurements of past tokens and calls; meme coins are extremely risky and most go to zero.