Brazil Presidential Election 2026

Flávio Bolsonaro is 86.75% on Polymarket and 87.5% on Kalshi to win Brazil's October 25 runoff, up two to three points since Tuesday; Lula is 13.5% and 12.5%.

The flow still runs against the price. Polymarket's outright turned $2,829,100 in 24 hours, $2,091,431 of it on Lula's leg against $737,669 on Bolsonaro's. Kalshi's turned $422,971, and there too the Lula leg took more, $296,472 to $128,642.

The margin boards have moved out. A narrow Bolsonaro win was the modal bucket on both; now Kalshi's leads with 3–6% at 34.5%, just ahead of 0–3% at 31.5%, and Polymarket's with 4–8% at 47.5%, more than double under 4% at 22.5%.

Election calendar.

Four venues, one question, within four points: 86.75% for Flávio Bolsonaro on Polymarket, 87.5% on Kalshi, 86% on Manifold and 83.5% on PredictIt, whose book did not trade. Lula is 12.5% to 16.5% across the four.

Polymarket carries the flow, $2.83M to Kalshi's $422,971, and most of it is on the underdog: $2,091,431 on Lula against $737,669 on Bolsonaro.

Both exchanges list a margin board for the second round, in different buckets. Kalshi, left: Bolsonaro by 3–6% at 34.5% and by 0–3% at 31.5%, then 6–9% at 19.5%, with a narrow Lula win at 9.5%, on $11,870. Polymarket, right: Bolsonaro by 4–8% at 47.5%, under 4% at 22.5% and 8–12% at 16.3%, with Lula by under 4% at 10.5%, on $172,551.

Polymarket's board has grown about twelvefold since Tuesday, and its busiest legs are the two leading buckets: $44,082 on 4–8% and $38,230 on under 4%.

The runoff is a two-way race, so one contract carries it. Flávio Bolsonaro to win the presidency is 87.5% on Kalshi and 86.75% on Polymarket, less than a point apart.

His Kalshi leg turned $128,642 and his Polymarket leg $737,669. Kalshi's open interest is 1,041,482 on Bolsonaro against 1,194,658 on Lula, so the larger standing position is still on the man priced at 12.5%.

• October 25. The runoff settles the outright on all four venues. Kalshi's book lists settlement that day; Polymarket's board carries its first-round date and trades on.
• The exchanges agree. Kalshi 87.5%, Polymarket 86.75%, Manifold 86%, PredictIt's untraded book 83.5%.
• Whether Lula's leg finds a floor. He was about 37% on election morning and is 12.5% to 13.5% now, yet his leg took $2,091,431 of Polymarket's day.
• The margin. Bolsonaro by three to eight points is now the modal outcome: 3–6% at 34.5% on Kalshi, 4–8% at 47.5% on Polymarket.
• Volume. Polymarket's outright turned $2.83M and Kalshi's $422,971.