Election Betting Prices Can Be Moved With $3,500

As voters in the US head to the polls on Tuesday, $431 million has already been invested in prediction markets for congressional races. According to research by the Anti-Corruption Data Collective (ACDC), in 96% of congressional markets with a live order book, the price can be moved by 5 cents with $3,500 or less in capital. This holds true even during a period when trading volume is rising.

ACDC Research Associate Michelle Kendler-Kretsch told Gambling Insider that the main concern is that these prices get circulated as evidence that a candidate is winning. Kendler-Kretsch said they were surprised by how easily the markets could be moved when they published their first study in September. In her view, many markets lack enough volume for another trader to quickly trade against a move.

The research was published on November 2 and covers 28,845 congressional markets on Kalshi, Polymarket and Polymarket US. Betting volume has nearly tripled compared with the 2024 congressional elections. The number of markets is 61 times higher than in the previous congressional cycle. The money is not evenly spread across all markets. According to ACDC's latest data, in 66% of live congressional markets the price can be moved by 5 cents with less than $100 in capital. Only 244 markets require more than $10,000 to do the same. Even in the most expensive market in each of the 470 races, the price can be changed by 5 cents in 90% of cases with less than $25,000 in capital.

The calculations show how far a price can be moved, but they do not show whether anyone is trying to manipulate an election. ACDC says it cannot tell from trade records why a bet was placed. Kalshi, meanwhile, introduced new transparency tools in October, including low-volume alerts and forecast accuracy measurements. Kendler-Kretsch said the alerts are useful for users who are unfamiliar with prediction markets, but also revealed that many contracts trade very little.