PoderData found a 50-50 race and CNT/MDA had Flávio ahead 50.5% to 49.5%. Polymarket's contract on a Flávio win slipped 1.4 cents, and its biggest drop came in an hour when no poll was released.
Brazil's pollsters now agree that the presidential runoff is close to a coin flip. The prediction market does not.
Two new surveys released Friday put the race between President Luiz Inácio Lula da Silva and Flávio Bolsonaro inside a single point. The first, from PoderData, came out around 6:15 a.m. Eastern and showed a 50-50 split of valid votes. PoderData interviewed 3,000 people by phone from Oct. 13 to 15, with a 1.8-point margin of error, and its previous two rounds had Flávio up 53-47 on Oct. 8 and 51-49 on Oct. 13. In a little over a week, his lead in that series has gone from six points to zero.
Four hours later, CNT/MDA had Flávio at 50.5% of valid votes and Lula at 49.5%, or 46.8% to 45.9% counting all responses. Its interviewers spoke to 2,014 people in person over the same three days, for a 2.2-point margin. Rejection was slightly higher for Lula, at 48.8%, than for Flávio, at 46.6%.
Of 12 polls with fieldwork between Oct. 3 and Oct. 15, Flávio was numerically ahead in 10, Lula in one, and one was tied, according to a compilation of the surveys.
The price
Polymarket's contract on a Flávio win stood at 78.1 cents at 4:47 a.m. Eastern. It was at 78.35 cents by about 6:10 a.m. and held there, then fell from about 78.3 cents at 8 a.m. to 76.4 cents by 8:55 a.m., a drop of about 1.9 cents in under an hour with no poll release. It touched a low of 76.25 cents in the late morning, after the CNT/MDA release, and stood at 76.7 cents at 1:46 p.m.
The net change from 4:47 a.m. was a loss of 1.4 cents. A 76.7-cent price means a trader risks about 3.3 dollars to win one on Flávio, by this publication's arithmetic.
The sequence does not fit a simple story. The price ticked up just before the tied PoderData poll was published, then held, and its biggest drop came in an hour when no Brazilian poll was released. No catalyst was evident for the 8 a.m. hour.
Brazilian stocks rose. The Ibovespa gained 0.55% to 205,450 in the morning, on a day BTG Pactual upgraded Brazil to overweight.
Polls versus price
Set side by side, the polls and the price disagree. Five recent polls sit within two points, two of them at or within one point of a tie. A price near 77 cents treats Flávio as a clear favorite.
The two are not measuring the same thing. Polls estimate how people would vote today, within a margin of error. The contract prices the outcome on Oct. 25 under Polymarket's rules, and it reflects what traders believe about turnout, late shifts and poll bias. A market-implied price is not an objective probability.
Market implications
One reading is that traders are counting leads, not margins. Ten of 12 recent surveys had Flávio in front, and a candidate who is ahead almost every time, however narrowly, may be a stronger favorite than any one poll's sampling error suggests.
A second reading is that the price is out of line. When two pollsters on the same morning find a tie and a one-point race, the honest description is a toss-up, and a 77-cent contract has a long way to fall if Sunday's debate or a late survey tips toward Lula.
What to watch
Flávio's Globo interview on Friday evening and Sunday's Band debate come first, followed by AtlasIntel on Monday, Quaest on Oct. 21, a second debate on Globo on Oct. 23 and the vote on Oct. 25. If the PoderData series, which has already moved six points, shows Lula ahead, a contract near 77 cents would face its first real test; if it does not, the market's confidence will look better founded.