STF orders probe into paid posts that promoted Flávio on Polymarket

Supreme Court minister Flávio Dino ordered the Federal Police (PF) to investigate who paid foreign accounts on X to promote Flávio Bolsonaro using probabilities from the Polymarket platform, in an order issued Tuesday, 27 October 2026. Dino demanded to know “who contracted and paid for the posts, where the funds came from and whether the campaign participated or was aware,” he wrote in the measure.

What prompted the investigation

The posts labelled on X as paid partnerships followed an update on 20 September 2026 from Polymarket’s own account that put Flávio’s chance of victory at a record 58%. At least 11 foreign accounts shared those probabilities that week without clarifying who had financed them. Rival party Missão (Mission Party) alleged that Polymarket paid for the posts; that claim remains unproven.

Missão and its presidential candidate, Renan Santos, filed a complaint with the Superior Electoral Court (TSE) on 23 September 2026 against the five accounts and X Brasil, arguing that posts fostered by Polymarket amount to foreign funding, which is prohibited by Brazilian electoral law.

Scope of Dino’s order

Dino described Polymarket as a prediction-markets platform banned in Brazil and opened the inquiry under the Arguição de Descumprimento de Preceito Fundamental (ADPF) 1178, a case framed as one of national sovereignty. He ordered a separate PF investigation under Supreme supervision, citing “the possible participation of members of the National Congress in the investigated facts.”

The order requires the PF to probe, in addition to the allegedly paid posts, four further lines of inquiry:

1. Conversations between the US group Rockbridge Network and Brazilian businessmen.

2. Links between Rockbridge representatives and Tallis Gomes and Pedro Sang, associated with Flávio’s campaign.

3. Any relationship between campaign financing and Brazil’s rare-earths reserves.

4. Possible algorithmic manipulation by technology platforms.

Dino made clear that opening an investigation is not a conviction. The PF must establish who paid, the origin of the funds and whether anyone in Brazil, including the campaign, knew of the commercial arrangement.

The posts and the accounts involved

On 20 September 2026 Polymarket’s X account posted: “BREAKING: Flávio Bolsonaro surges to an all-time high in Brazil's presidential election odds, with the first round just two weeks away. 58% chance.” One minute later the account replied with a link to the market that included the tracking code “via=x-afr2.”

Within a day, posts marked as paid partnerships appeared sharing those odds from accounts Geiger Capital, Visegrád 24, former US congressman Matt Gaetz, UHN Plus and Eric Daugherty. Gaetz, with 3.4 million followers, wrote that Flávio could save Brazil. Visegrád 24 has about 1.4 million followers; it is a Warsaw-based outlet run by the Intermarium Foundation, a Pennsylvania nonprofit that interviewed Flávio in February.

X’s paid partnership label shows the author was paid, but not by whom. Polymarket has been X’s official prediction-markets partner since June 2025. Eduardo Bolsonaro, Flávio’s brother, reshared some of the posts.

Public reactions and prior procedures

Polymarket has said its markets “reflect trades made by their participants” and that they “are not polls or official projections and do not represent support for any candidacy.” It added that it is “available to share our technical knowledge with authorities” while rules for prediction markets are drafted. Polymarket has not stated whether it paid the accounts.

Flávio Bolsonaro denied any illegal conduct and no published evidence shows his campaign organised or was aware of the posts. UHN Plus said it will defend “its editorial independence and journalistic activity.”

Before this order, on 25 September 2026 minister André Mendonça rejected removing the posts before hearing the parties and ordered X Brasil to preserve data on the accounts and paid partnerships. There is not yet a ruling on the merits.

Business and funding links

Dino’s order also probes Rockbridge Network, a US conservative donor group co-founded by JD Vance and Chris Buskirk. Pedro Sang was named CEO of “Rockbridge Network Brasil” and worked on Flávio’s campaign in São Paulo; Tallis Gomes appears as a Rockbridge member. Both deny brokering campaign funding and Rockbridge says its Brazilian entity never operated.

In the United States, Rockbridge founders and donors back Polymarket. The firm 1789 Capital, cofounded by Rockbridge-aligned figures, led Polymarket’s funding round of $1 000 000 000 at a $21bn valuation in August. Founders Fund, linked to Peter Thiel, led the 2024 Series B. Donald Trump Jr., a partner at 1789 Capital with ties to Rockbridge Network, joined Polymarket’s advisory board in August. There is no investigation linking these connections to the paid posts.

Other proceedings involving Flávio

Flávio lost the presidential election to Luiz Inácio Lula da Silva on 25 October 2026. He also faces a separate Supreme Court probe for alleged money laundering related to his associate, lawyer Willer Tomaz, in which betting appears as a central element. Documents obtained by piauí magazine indicate Flávio was an indirect partner in Best Bet, a licensed operator in Rio managed by companies linked to Tomaz.

A Ministry of Finance note obtained by UOL identified Willer Tomaz as the largest individual bettor by deposits in 2025. Both Tomaz and Flávio deny wrongdoing. Minister Alexandre de Moraes froze up to R$6bn of Tomaz’s assets and cancelled Flávio’s passports when he did not hand over documents on 27 October 2026; police later annulled the passport cancellations.

Polymarket markets related to the legal situation

Polymarket lists contracts about Flávio’s legal status. Its market “Flávio Bolsonaro charged or arrested by October 31?” traded between 36% and 47% on 27 October 2026, with volume of around $16,700. A contract on whether he returns to Brazil before 31 March 2027 implied 28% probability at close, while a new market on his arrest before 2027 shows no volume yet.

The platform also offers markets on political impact: it gives 51% that Donald Trump will meet Flávio this year and 6% that Brazil’s presidential election is annulled before 31 December. On Jair Bolsonaro it places 20% chance of freedom and 16% of a pardon by 31 March 2027. A market on whether minister Alexandre de Moraes will leave the Supreme Court accumulated about $258,000 in volume and trades at 8%. Most of these markets are thin and prices can move sharply on a single trade.

Dino’s order does not rule on those new markets or on any possible relation between them and the paid posts.

“If payment and foreign origin of the funds are confirmed, the facts may also constitute a violation” of electoral law and TSE rules, Dino wrote in the order.

I am Renata Quiroga, Betting Markets Correspondent, and this article summarises the judicial measure and the publicly documented connections to date.