September 17, 2026

1. Prediction market

The presidential election winner contract widened the spread for a second day, this time with only one side moving. In the confirmed reading of September 17, at 13:21 BRT, Flávio Bolsonaro stands at 54.70% (USD 10.88M), 0.95pp above the 53.75% of September 16, and Lula remains at 44.50% (USD 11.19M). The distance went from 9.25pp to 10.20pp, with total presidential volume at USD 150.87M accumulated.

Flávio sits 0.40pp below his series high, of 55.10% on September 10. Renan Santos gave up 0.20pp, to 1.15% (USD 13.60M), below the lowest value of the recorded readings in his series, and Augusto Cury 0.10pp, to 0.15% (USD 4.95M). The largest accumulated volume in the book is still Tarcísio de Freitas's contract, USD 14.08M, flat at 0.05%.

The day's biggest move is in the first-round third-place contract. Renan Santos rose 7.50pp, to 44.00% (USD 324 thousand), and passed Augusto Cury, who fell 2.60pp, to 42.90% (USD 215 thousand). Ronaldo Caiado gave up 3.00pp, to 12.50% (USD 133 thousand). In the runner-up contract, Flávio rose 1.00pp, to 76.50% (USD 890 thousand), and Lula gave up 1.20pp, to 22.65% (USD 780 thousand).

The Supreme Court impeachment contract stands at 5.05% (USD 91 thousand), 0.20pp above the previous day, with USD 199 of new money in the book. In the Senate contract the Liberal Party stands at 84.00% (USD 261 thousand), 0.50pp above September 16.

2. What the polling houses recorded

AtlasIntel, with Bloomberg, surveyed 5,018 voters online from September 11 to 16, margin of 1pp and register BR-06221/2026. In the first round Lula has 44.1% and Flávio 41.7%, and the distance within the house narrowed from 5.6 to 2.4 points since September 10. In the runoff Flávio has 47.2% and Lula 46.8%, against 46.4% to 46.2% in the previous round. Lula wins the other four pairs, and government approval is 45.4% against 53.6% disapproval, according to Gazeta do Povo and CartaCapital.

PoderData conducted 3,000 automated telephone interviews from September 13 to 16, margin of 1.8pp and register BR-00360/2026. The runoff gives Flávio 46% and Lula 44%, the same 2 points as September 10, and the first round Lula 37% and Flávio 36%, with Cury at 8%, according to CNN Brasil and CartaCapital. Gerp surveyed 2,400 voters by telephone from September 14 to 16, margin of 2pp and register BR-00535/2026. It gives the first round to Flávio by 40% to 37% and the runoff by 50% to 43%, the same 7 points as September 9, according to Exame and CNN Brasil.

The Superior Electoral Court register also set Datafolha and 100 Cidades for September 17, and this briefing does not carry numbers from either.

Poll calendar, next 7 days

Polls registered with the Superior Electoral Court with release scheduled between Sep 18 and Sep 24. Being on the table does not mean release is confirmed, because houses can delay or cancel a release. Filters applied: national scope and a sample of 1,000 or more.

Source: the public Superior Electoral Court register via the AFOS API. Samples of 3,000 or more in bold. The table lists the 6 national polls in the window, and 43 registrations from the same period were left out by scope or by sample. The status is registered, not published.

3. What the press covered

The president of the Supreme Court, Edson Fachin, removed from the September 23 agenda the judgment of the request to investigate André Mendonça's conduct as rapporteur of the Master case, without setting a new date, according to Poder360 and Gazeta do Povo. The analysis on investigating Alexandre de Moraes remains stalled on Flávio Dino's review request of September 15, which has a deadline of up to 90 days.

The dispute between justices moved to social media. Gilmar Mendes wrote on X that Mendonça acted as a "campaign puppet" and "electoral pixuleco" and defended Prosecutor General Paulo Gonet, according to Poder360. Mendonça replied in a statement that lifting the secrecy was a reasoned decision within his authority and defended an ethics code for the Supreme Court, according to Correio Braziliense.

4. Divergences of the day

In summary

The spread widened with only one side moving. Flávio rose 0.95pp, to 54.70%, 0.40pp from the series high, and Lula stayed at 44.50%. The distance went to 10.20pp.

Three national polls, three stable distances. AtlasIntel, PoderData and Gerp put Flávio ahead in the runoff by 0.4, 2 and 7 points, each close to what it measured in its previous round. The movement in the polls is in the AtlasIntel first round, where Lula's lead fell from 5.6 to 2.4 points.

The Supreme Court postponed the other side of the crisis. Fachin took the judgment on Mendonça off the agenda, and Gilmar and Mendonça traded public accusations on the same day.

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Fontes consultadas

matérias com link direto para a notícia (veículos âncora):

• Brasil de Fato · Atlas/Bloomberg: Lula keeps lead over Flávio in the first round
• Gazeta do Povo · AtlasIntel releases poll for president
• CartaCapital · Lula and Flávio Bolsonaro remain tied in the runoff, AtlasIntel shows
• CNN Brasil · PoderData/Aya: Flávio has 46% in the runoff; Lula, 44%
• CartaCapital · PoderData poll shows tie between Lula and Flávio in first and second rounds
• Exame · Gerp poll: Flávio Bolsonaro has 40% and Lula, 37%, in the first round
• CNN Brasil · Gerp: Flávio has 50% in the runoff; Lula, 43%
• Poder360 · Fachin postpones judgment of the request to investigate Mendonça
• Gazeta do Povo · Fachin cancels Supreme Court session that would review Moraes's request against Mendonça
• Poder360 · Gilmar defends Gonet and calls Mendonça an "electoral pixuleco"
• Correio Braziliense · Mendonça rebuts criticism and defends publicity of decisions in the Master case

matérias secundárias (URL de redirecionamento, clique resolve à matéria):

• Poder360 · Flávio has 50% against Lula's 43% in the runoff, says Gerp
• Gazeta do Povo · PoderData releases new poll for president
• Bloomberg Línea · Lula and Flávio appear tied amid the Supreme Court crisis, according to Atlas poll
• O Globo · Fachin postpones judgment on Mendonça's conduct in the Master case scheduled for the 23rd
• Estadão · Fachin postpones judgment on Mendonça's acts in the case of messages between Moraes and Vorcaro

Fontes técnicas: Polymarket (live quotes via the AFOS proxy, reading confirmed on Sep 17 at 13:21 BRT), Superior Electoral Court register (official election polls).