Study: Manipulating Polymarket Odds Could Fool News Media
Those market odds in headlines might be bought for just $1 million.
Prediction markets like Polymarket are websites where people bet real money on future events, from elections to wars. News articles often quote these odds as if they are scientific polls: "Chances of a deal: 60%." But unlike a poll, anyone with a lot of money can push those odds in a certain direction.
A new study from researchers at New York University looked at over 173 million Polymarket trades and compared them to 6,990 news articles that mentioned prediction markets. They found that when a market suddenly jumped by at least five percentage points, news articles quoted it 33% more often in the following days. The size of the jump mattered less than whether the market was already famous.
The worrying part is the price of influence. The researchers calculated that moving a well-known market by five points and having that move show up in news costs roughly $700,000 to $1 million. That's a lot, but it's easily within the budget of large political donors, lobbying groups, or even foreign governments. And because newsrooms treat these big markets as trustworthy, a single coordinated trade could create the appearance of a trend that doesn't really exist.
The study doesn't prove this has happened. It just shows how easy it would be. As prediction markets become more popular, newsrooms need to be careful about treating every market move as genuine wisdom of the crowd — sometimes, it's just a well-funded bet.
- News articles quote prediction markets like Polymarket as if they were impartial polls.
- After a sudden $1 million trading move, a market is 33% more likely to be cited in the news.
- Big, famous markets offer the best target for manipulation because they get the most coverage.
Why It Matters
When you read "the market says 60%", that number may have been swayed by a rich manipulator — undermining your trust in news.