Kalshi settled its Flávio Bolsonaro contract "No" 61 minutes after the electoral court declared Lula the winner. Polymarket resolved its contract about three hours later. On Monday, Brazilian assets showed how much money had followed the pre-vote pricing.
Flávio Bolsonaro says he will not accept the result of Brazil's presidential election. The two largest prediction markets did not wait for him.
Brazil's electoral court declared President Luiz Inácio Lula da Silva reelected at 8:08 p.m. Eastern on Sunday. Kalshi closed its market on the election at 8:38 p.m. and settled it at 9:09 p.m., 61 minutes after the declaration: Bolsonaro "No," Lula "Yes." Polymarket's contract on whether Bolsonaro would win closed at 11:17 p.m. Eastern and resolved "No," about three hours and nine minutes after the declaration.
Bolsonaro's call for an annulment, which targets a Supreme Court justice's order extending voting by two hours, did not delay either settlement.
How the rules handled it
Both venues wrote their contracts for this situation. Kalshi's market resolved "Yes" for a candidate who "has won the 2026 Brazilian presidential election," and its rules said it "will close and expire after a winner is announced." Polymarket's contract resolves on "a consensus of credible reporting," and in cases of ambiguity on "the official results" reported by the electoral court.
The court's declaration was both the announcement and the official result. A refusal to concede, without a ruling that changes the outcome, did not create the ambiguity that Polymarket's rules contemplate. Members of the court have privately assessed that the annulment request will not prosper, G1 reported, and Justice Kassio Nunes Marques said the extension did not alter the election.
The size of the book
The volumes were large. Kalshi's Bolsonaro contract traded about 18.7 million contracts over its life and had about 9.2 million contracts of open interest when it settled. Its Lula contract traded about 10.2 million. Polymarket's Bolsonaro market traded about $62.2 million over its life, and the full Brazil election event about $249.1 million.
Prediction markets are banned in Brazil, so that money came from traders outside the country.
What the other markets showed
On Sunday afternoon, both venues priced Bolsonaro at 81 to 82 cents. That price did not predict his victory: it left an 18% chance of the outcome that occurred. What it did show was where the consensus of traders sat, and Monday showed how much capital had sat with it.
The Ibovespa triggered a circuit breaker at the open and fell as much as 17.34%. The dollar rose more than 12% against the real at its peak, and the iShares MSCI Brazil ETF was down about 21% by early afternoon. Itaú Unibanco's U.S. shares fell about 22%. A move that size is consistent with investors having positioned for the outcome the prediction markets favored, and unwinding it at once.
Two readings
One reading is that the venues worked cleanly. Rules written in advance named the deciding authority, both platforms settled within hours on the same answer, and a political challenge did not leave millions of contracts in limbo.
The other is that speed carries its own risk. If an electoral court ever did reopen a result after settlement, the contracts would already be paid out. The rules quoted above speak to ambiguity before a market settles; they do not describe what would happen after.
What to watch
Any formal annulment filing and the electoral court's response, any dispute raised on either venue, the B3 close and the finance minister nomination.