Brazil prediction markets moved to Bolsonaro before first-round upset

Prediction-market odds moved in Flávio Bolsonaro’s favor more than two weeks before Brazil’s first-round presidential result, while Datafolha polling had put Luiz Inácio Lula da Silva ahead.

A Cryptonews analysis said the market lines first crossed in Bolsonaro’s favor on Sept. 12. Bolsonaro subsequently led the first round with 47.03% of the vote, or more than 56 million votes, against Lula’s 45.16%, or 53.8 million.

The result reversed Datafolha’s projected order of finish. Its polls had put Lula at 42% and Bolsonaro at 38%. Reuters’ election results page described the first round as the first substantial measure of candidate support beyond polling and said its results data came from Brazil’s Superior Electoral Court.

No candidate cleared the 50% threshold needed to win outright, requiring a runoff. Lula said he had expected to win in the first round, adding: “Starting tomorrow, a new campaign begins. Bolsonaro represents uncertainty for the country.”

The prediction-market lead grew to 86% after the first-round result was known, according to the analysis. It argued that the episode strengthened the case for prediction platforms as political-data tools, while acknowledging that Brazil’s Central Bank had banned such platforms.

The analysis drew a comparison with the 2024 U.S. presidential campaign, when it said conventional polls showed a tight race, sometimes favoring Kamala Harris, while Kalshi and Polymarket each put Donald Trump ahead by 10 percentage points. Its broader conclusion that prediction markets are more reliable than polls remained an analyst view, including its contention that commissioned polling can favor the party paying for it.

Bolsonaro and Lula are due to face each other in the runoff on Oct. 25.