Flávio Bolsonaro recovers from a midweek dip in Brazil's race

Polymarket and Kalshi both put him near 80% to beat Lula, though below last week's 88%.

In one line: Flávio Bolsonaro beats Lula in the 25 October runoff by under four points; at 81%, traders rate his win as surer than so close a race allows.

Polymarket's contract on Flávio Bolsonaro winning Brazil's presidency still trades 13 days past the 5 October resolution date the venue lists, and its rule keeps it open through any second round. Traders cut his chance from 88% on 11 October to a low of 75% on 15 October, then pushed it most of the way back. The contract stands at 81%, up 6 points since that low and up 2.6pp in the last 24 hours, yet still down 7 points over the week.

The rule "includes any potential second round" and turns to "Other" only if no result is known by 30 June 2027. The part not yet met is the second-round result, so the listed date follows the 4 October first round and does not mark the end of the contract. Polymarket at 81% and Kalshi at 79% show two venues reaching the same reading from separate pools of money. Lula's contract stands at 20%. The margin contracts on the second round put 42% on a Bolsonaro win by less than four points, 30% on four to eight, 9% on eight to twelve and 3% on twelve or more.

Those margin prices are the better guide to what traders expect. They put more weight on a win by under four points than on any wider result, so the market's own central case is a close race. A race that close is one a four-point shift can reverse, which sits uneasily with a four-in-five chance. The slide to 75% this week showed how fast that confidence can give way. The case for the price is that Polymarket and Kalshi agree and traders lifted the contract 6 points off its low, and a comfortable Bolsonaro win would bear them out.

Flávio Bolsonaro wins the second round by less than four points, and 81%, which prices a contract still open past its listed date, overstates how safe that win is. A Lula win, or a Bolsonaro margin of four points or more, in the official count of the 25 October runoff proves this call wrong.