An NBC News analysis found that in this election cycle, approximately $200 million has been wagered in prediction markets, where users have bet on election outcomes across the country.
According to the Commodity Futures Trading Commission (CFTC), a prediction market is a platform where users buy and sell contracts tied to the outcome of future events. The price of a contract reflects the market-implied probability of an outcome.
For example, a contract trading at 55 cents implies the market estimates a 55% chance the event will occur. Trading volume reflects how actively a market is being traded. Prediction markets are speculative, which means market prices do not guarantee the outcome of an event.
According to economics professors Paul W. Rhode and Koleman Strumpf, prediction markets in elections date back centuries. The first modern version of a prediction market was the Iowa Presidential Stock Market, a program that three University of Iowa professors started in 1988 to test whether markets were more accurate than polls. Their research found prices outperformed the polls three-fourths of the time from 1988 to 2004. In 2023, the prediction market platform Kalshi began offering contracts on which party would control Congress following the 2024 elections. In the 2024 presidential election, users of Polymarket, another prediction market platform, spent $3.2 billion on contracts.
Polymarket data on 504 congressional and gubernatorial general elections as of July 27 shows that Democrats are favored in 264 races and Republicans in 236. There are no odds available for this year's general elections in California's 40th Congressional District and Maine's 2nd Congressional District.
In most of these general elections, one party is viewed as having an 81% or higher chance of winning. Seventy races are viewed as more competitive, with one party having a 51% to 80% chance of winning.
According to Polymarket, the following races are the closest congressional and gubernatorial general elections this year:
- The closest U.S. House race is between incumbent Rep. Monica De La Cruz (R) and Bobby Pulido (D) for Texas' 15th Congressional District . Pulido has a 50% chance of winning the race, compared to De La Cruz's 48%.
- The closest U.S. Senate race is between James Talarico (D) and Ken Paxton (R) in Texas . Paxton has a 56% chance of winning the race, compared to Talarico's 44%.
- The closest gubernatorial race is in Alaska. Four candidates will advance from the Aug. 18 primary to the general election . A Democratic candidate has a 49% chance of winning the race, compared to a Republican candidate's 47%. Among 2026 congressional and gubernatorial general elections, this is the only race in which neither party is favored by at least 50%.
To read more about prediction markets, click here. To read more about elections happening this year, click here.
