Quaest put Flávio Bolsonaro two points ahead of President Lula within the margin of error. Polymarket's price on a Flávio victory slipped to about 82.5 cents but still implies better than four-to-one odds.
The latest poll of Brazil's presidential runoff and the leading prediction market agree on who is ahead. They disagree sharply on by how much.
A Quaest survey released Wednesday evening showed Flávio Bolsonaro at 46% and President Luiz Inácio Lula da Silva at 44%, with 9% planning to vote blank or null or not to vote and 1% undecided. The poll of 2,154 voters, conducted Oct. 10 to 13, has a margin of error of two percentage points, making the race a statistical tie. Ninety-one percent of respondents said their choice is final.
Both candidates face high rejection. Fifty-four percent said they would not vote for Flávio under any circumstances, and 53% said the same of Lula.
The price
Polymarket's contract on Flávio winning traded at 85.05 cents through Wednesday afternoon. It slipped after the poll, with the largest hourly decline, of 1.4 cents, between 7 p.m. and 8 p.m. ET, and stood at 82.7 cents at 4:46 a.m. Thursday and 82.55 cents at about 6:10 a.m. That is down from 86.25 cents 24 hours earlier.
The direction is notable. The poll showed Flávio ahead, yet his price fell. One possible explanation is that a two-point lead is narrower than the 49% to 45% margin in the previous Datafolha poll on Oct. 8. But the sequence alone does not prove the poll moved the market.
The gap
Even after the decline, a price near 82.5 cents implies roughly an 83% chance of a Flávio victory. A poll lead of two points inside a two-point margin of error does not, on its own, describe a race that lopsided.
One reading is that traders are pricing factors beyond the topline: an electorate that says its mind is made up, and Flávio's lead in each of the last two major polls.
The other is that the market is overconfident and slow to adjust. If the gap between polls and prices persists, either the polls are missing something or the price has room to fall further.
What to watch
A new Datafolha poll due Thursday evening, the televised debate on Sunday, Oct. 18, which both candidates have confirmed, a second debate on Oct. 23 and the runoff on Oct. 25.