Short Answer

The model assigns meaningfully higher odds to Umaro Sissoco Embaló (45.1%) than the market (25.1%). However, the 2025 Guinea-Bissau Presidential Election was annulled, making any candidate's victory impossible.

1. Market Behavior & Drivers

This market displays a sideways price channel with an implied probability that has ranged from 1.1% to 16.3%. The contract opened at 16.2% and currently sits at 14.4%. The most significant feature of this market is the complete absence of trading activity. With zero contracts traded across 336 data points, the price fluctuations are not driven by participant sentiment or new capital. Instead, the price movement is likely an artifact of an automated market maker's pricing curve or algorithmic adjustments in an illiquid environment.
The market's low valuation reflects a fundamental disconnect with reported events. The contract resolves based on Umaro Sissoco Embaló winning a 2025 presidential election. However, context indicates Embaló was overthrown in a military coup in November 2025. Subsequent general elections are now reportedly scheduled for December 2026. This makes the premise of the market contract—a 2025 victory for Embaló—a highly improbable scenario. The lack of volume suggests traders have not found the contract's terms to be a viable vehicle for expressing a view on Guinea-Bissau's political future.
  • Umaro Sissoco Embaló cannot win; he was overthrown by a military coup.
  • Fernando Dias da Costa cannot win; he was arrested after the coup.
  • All candidates cannot win; the 2025 election was annulled following a coup.

Current Context

Guinea-Bissau navigates a post-coup transition towards scheduled 2026 elections. Presidential and legislative elections are scheduled for December 6, 2026 [1][2][3][4]. This follows a military coup on November 26, 2025, which overthrew President Umaro Sissoco Embaló [1][2][3][4]. A constitutional referendum is also set for August 30, 2026, aimed at shifting the country to a presidential system [1][5][6]. This system would grant the president increased power, including the ability to appoint the prime minister and dissolve parliament [1].
Domestic political tensions complicate the transition amid regional mediation. The continued detention of opposition leader Domingos Simões Pereira strains the political atmosphere [7]. His imprisonment has drawn international condemnation and led to a diplomatic freeze in relations with Cape Verde [7][8]. Senegal, operating under the ECOWAS mandate, leads a diplomatic mediation mission to ensure a transition to constitutional governance [5][6]. The upcoming referendum and the December elections are critical milestones in this process [5][6]. Guinea-Bissau electoral law prohibits the publishing of public opinion polls, making prediction market or polling data unavailable [4].
Discrepancies exist regarding official presidential election date confirmations. As of August 18, 2026, expert-curated sources from Ballotpedia contain no documented developments or specific election dates concerning a 2026 presidential election in Guinea-Bissau [9].
Sources (9)
  1. 1Guinea-Bissau to hold referendum on expanding presidential power | Africanewsafricanews.com
  2. 2Guinea-Bissau junta sets election date following last year's military takeover | AP Newsapnews.com
  3. 3Guinea-Bissau set to hold general elections on December 6 | Africanewsafricanews.com
  4. 42026 Guinea-Bissau general electionen.wikipedia.org
  5. 5Guinea-Bissau Mediation Mission Sparks New Hope for Constitutional Ruleafricanquarters.co
  6. 6Senegal leads Guinea-Bissau transition plan with new diplomatic push - Niger Reportnigerreport.net
  7. 7Guinea-Bissau: Opposition leader house arrest raises stakesdw.com
  8. 8Tensions as Guinea-Bissau freezes ties with Cape Verde over claims of interference | Africanewsafricanews.com
  9. 9International ballot measures, Africa - Ballotpediaballotpedia.org

2. Price Chart

Historical Price (Probability)

Outcome probability
Date

3. Significant Price Movements

Notable price changes detected in the chart, along with research into what caused each movement.

📉 August 14, 2026: 8.8pp drop

Price decreased from 22.5% to 13.8%

Outcome: Fernando Dias da Costa

What happened: The research indicates that the described market movement for a "Guinea-Bissau Presidential Election" on August 14, 2026, with Fernando Dias da Costa as an outcome and an 8.8 percentage point drop, cannot be attributed to any discernible cause. There is no evidence of a presidential election occurring in Guinea-Bissau involving Fernando Dias da Costa on that date, nor any record of an 8.8 percentage point drop associated with such an event [1][2]. Instead, on August 14, 2026, Guinea-Bissau launched a national campaign for a constitutional referendum, which is scheduled for August 30, 2026, and may influence future presidential elections [3][4]. Given the absence of the stated market event, social media activity was irrelevant to the specified price movement.

📈 August 13, 2026: 12.1pp spike

Price increased from 10.5% to 22.6%

Outcome: Fernando Dias da Costa

What happened: The stated 12.1 percentage point spike in the prediction market for Fernando Dias da Costa on August 13, 2026, appears to be based on misattributed data. This specific metric is consistently associated with unrelated events, such as UK 2024 parliamentary election swings or 2026 Tamil Nadu election data, rather than Guinea-Bissau politics [5]. Furthermore, a similar percentage increase was documented in 2017 school board elections, suggesting a potential misattribution to this query [6]. Consequently, identifying a primary driver for a price movement that seemingly did not occur in this specific market context is not possible, rendering social media as irrelevant.
Sources (6)
  1. 1Elections Ballotpedia is covering in August 2026 - Ballotpedia Newsnews.ballotpedia.org
  2. 2International ballot measures, Africa - Ballotpediaballotpedia.org
  3. 3Guinea-Bissau launches national campaign ahead of constitutional referendum – Channel Africachannelafrica.co.za
  4. 4Guinea-Bissau: the draft Constitution strengthening the powers of the president is not unanimously supported. -beninwebtv.bj
  5. 5Tamil Nadu 2026 Election · 85.1% Turnout Dashboardtn-dashboard-app.vercel.app
  6. 6Competition in school board elections increases 31 percent in three years - Ballotpediaballotpedia.org

4. Market Data

Contract Snapshot

For a specific listed candidate, a "YES" resolution is triggered if they win the Guinea-Bissau Presidential Election, which includes any potential second round; otherwise, it's a "NO" resolution. The first round of the election is scheduled for November 23, 2025, with a potential second round on November 30, 2025. If the election's winner is not known by December 31, 2026, 11:59 PM ET, the market will resolve to "Other," with final resolution based on credible reporting, prioritizing official results from Guinea-Bissau's National Election Commission (CNE) if there is ambiguity.

Market Discussion

Here's a summary of the market discussion for the Guinea-Bissau Presidential Election:

1. Main viewpoints being discussed by traders: The market generally identifies Fernando Dias da Costa and Umaro Sissoco Embaló as the primary contenders, with Fernando Dias da Costa currently holding a narrow lead in trader pricing over Embaló. The vast majority of other candidates are considered longshots, trailing far behind. One individual trader, however, expresses a strong conviction that Mamadu Iaia Djaló is the "clear front runner" and should be priced at 80%, significantly contrasting with the current market odds. 2. Key arguments for YES vs NO: The discussion does not contain explicit arguments for or against specific candidates. Instead, the market's probabilities are influenced by the complex political landscape, including party negotiations, potential alliances or withdrawals among candidates, and the fragmented nature of the opposition. The absence of opinion polls means that trader positioning is driven by these evolving political dynamics. 3. Any notable insights or consensus: The market largely converges on Fernando Dias da Costa and Umaro Sissoco Embaló as the most likely winners. A key insight is that future shifts in probabilities are anticipated to stem from major endorsements, legal rulings concerning candidacies, or security developments in the coming months, rather than traditional polling data.

5. Trader Dashboard

This scorecard was computed Aug 18, 2026 and may not reflect current market conditions.

Trust profile
Event quality1
Poor

6. How might the outcome of the August 2026 constitutional referendum impact the campaign strategies of leading candidates like Umaro Sissoco Embaló and Domingos Simões Pereira?

Referendum verification statusNo verified information as of August 18, 2026 [1]
Proposed referendum dateAugust 30, 2026 [2][3][4][5]
Embaló election statusCleared for December 6, 2026, presidential elections [6][7]
Guinea-Bissau faces uncertainty regarding a potential August 2026 constitutional referendum. While there is no verified information or evidence of a scheduled constitutional referendum as of August 18, 2026 [1], reports indicate a referendum may occur on August 30, 2026. This proposed referendum aims to transition to a strongly presidential system, granting the president the power to appoint the prime minister and dissolve parliament [2][3][4][5].
A successful referendum would significantly boost Umaro Sissoco Embaló's campaign strategy. If these constitutional changes pass, establishing a strongly presidential system, Embaló would benefit from expanded presidential powers [2][3][4][5]. He has already been cleared by the ruling military junta to contest the December 6, 2026, presidential elections [6][7]. The opposition views these proposed changes as an attempt to consolidate presidential power and restrict democratic processes, specifically designed to favor Embaló's return to office [8].
Conversely, Domingos Simões Pereira would confront increased strategic obstacles if changes pass. As a leading opposition figure, Pereira is currently facing legal challenges from transitional military authorities, and his party and coalition have reportedly been sidelined and disqualified from electoral processes [9][10][6]. The opposition's concerns that the constitutional changes aim to restrict democratic processes and favor Embaló [8] suggest that such changes would further disadvantage Pereira's campaign efforts. The overall impact remains conditional on the referendum actually taking place, given the ongoing lack of verified scheduling information [1].
Sources (10)
  1. 1International ballot measures, Africa - Ballotpediaballotpedia.org
  2. 22026 Guinea-Bissau constitutional referendumen.wikipedia.org
  3. 3Guinea-Bissau to hold referendum on expanding presidential...africanews.com
  4. 4Guinea-Bissau Referendum Campaign Alarms Civil Societyriotimesonline.com
  5. 5Guinea-Bissau sets August 30 referendum on constitutional reform ahead of elections – Medafrica Timesmedafricatimes.com
  6. 6Guinea-Bissau Junta Moves to Clear Path for Embaló’s Election Bid Amid Dissent Supression – The Gambia Journalgambiaj.com
  7. 7Guinea‑Bissau’s Military Junta Sets Dec. 6, 2026 Election Date After Coup - NuvaPulsenuvapulse.com
  8. 8ECOWAS move sparks backlash in Guinea-Bissau - Radar Africaradarafrica.com
  9. 9Guinea-Bissau • Pereira goes on the offensive with drug trafficking accusations against Embaló - 22/09/2025 - Africa Intelligenceafricaintelligence.com
  10. 10Opposition sidelined as Guinea-Bissau elections neardw.com

7. What is the current legal status of detained opposition leader Domingos Simões Pereira and what are the primary obstacles to his participation in the 2026 election?

Current LocationLisbon, Portugal (as of August 18, 2026) [1][2]
Political Activity StatusBarred from political-party activities while in Portugal [1]
Legal StatusFaces charges related to 2023 and 2025 coup attempts and economic crimes [3][4][5]
Domingos Simões Pereira currently faces significant legal challenges and political restrictions. As of August 18, 2026, he is in Lisbon, Portugal, receiving medical treatment under authorization from the Guinea-Bissau Regional Military Court [1][2]. A key condition of his release and travel is a prohibition from engaging in any political-party activities while in Portugal [1]. In Guinea-Bissau, Pereira is subject to ongoing accusations of involvement in and financing alleged coup attempts in 2023 and 2025, in addition to economic crime charges that have previously led to his house arrest and imprisonment [3][4][5].
Judicial and administrative hurdles impede Pereira's 2026 election participation. His political coalition was previously barred from elections due to a late filing, and the Supreme Court disqualified his candidacy in 2025 [4][6][7]. These persistent judicial and administrative exclusions, combined with the active legal challenges and the potential for future imprisonment, form substantial barriers to his electoral prospects [3][4][5]. Furthermore, the current restriction on his engagement in political activities while abroad compounds these obstacles [1].
Sources (7)
  1. 1Domingos Simões Pereira Says He Is “Absolutely Free”...gambiaj.com
  2. 2Guinea-Bissau's imprisoned opposition leader allowed to...reuters.com
  3. 3Guinea-Bissau military court orders opposition leader back to jail | 95.5 WIFCwifc.com
  4. 4Guinea Bissau: Military court returns main opposition leader to prison – HCNTimes.comhcntimes.com
  5. 5Guinea-Bissau Country Report 2026bti-project.org
  6. 62025 Guinea-Bissau general electionen.wikipedia.org
  7. 7Guinea-Bissau opposition leader excluded from...trtafrika.com

8. How do the foreign policy platforms and key international alliances of Umaro Sissoco Embaló and Domingos Simões Pereira differ, particularly regarding ECOWAS and Cape Verde?

Embaló's ECOWAS Chairmanship2022 to 2023 [1]
Pereira's CPLP Secretary-General Term2008 to 2012 [2]
Bissau-Guinean-Cape Verde Diplomatic Status'Practical freezing' of ties [3]
Umaro Sissoco Embaló's foreign policy involves a complex relationship with ECOWAS. He served as the organization's chairman from 2022 to 2023, during which he led various regional mediation efforts, including missions to the Sahel and peace initiatives concerning Russia and Ukraine [1]. This period also saw escalating tensions between the Bissau-Guinean government under Embaló and Cape Verde, leading to a 'practical freezing' of diplomatic ties. This occurred after Cape Verdean appeals for the release of Domingos Simões Pereira, whom Bissau-Guinean authorities accused of involvement in coup attempts [3].
Domingos Simões Pereira prefers a Western-oriented, cosmopolitan leadership style. He has historical ties to international Portuguese-speaking organizations, having served as Secretary-General of the Community of Portuguese Language Countries (CPLP) from 2008 to 2012 [2]. In the current political landscape, while Embaló sought re-election in the 2025 presidential cycle, Pereira was administratively disqualified from the ballot [4][5][6].
Sources (6)
  1. 1The Political Crisis in Guinea-Bissau and the Failure of ECOWAS Mediation: Causes and Indicators – World Policy Hubworldpolicyhub.com
  2. 2Guinea-Bissau: Ex-PMs advance to runoff electiondw.com
  3. 3Guinea-Bissau Freezes Ties with Cape Verde Over Interference – Cabo Verdecabo-verde.cv
  4. 4EXPLAINER – Guinea-Bissau votes in a test of democracyaa.com.tr
  5. 5Guinea-Bissau’s president seeks second term in close election race | AP Newsapnews.com
  6. 6Embalo launches Guinea-Bissau campaign as rivals face exclusionradarafrica.com

9. Given the legal prohibition on public opinion polls in Guinea-Bissau, what alternative data sources or qualitative indicators are available to assess voter sentiment for the 2026 election?

Public Opinion PollsStrictly prohibited by Article 33 of Electoral Law [1][2][3]
Primary Sentiment AssessmentCrowd-reading at campaign rallies [4]
Other Qualitative SignalsCivil society reports, public protests, discourse analysis [5][4][6]
Article 33 of Guinea-Bissau's Electoral Law prohibits public opinion polls, necessitating alternative sentiment assessment. This legal restriction on disseminating poll results compels researchers to rely entirely on alternative data sources and qualitative indicators to gauge voter sentiment and the public mood in anticipation of the 2026 election [1][2][3].
Various qualitative indicators offer insights into public opinion. Key alternative methods include crowd-reading, which assesses public sentiment by observing the intensity and themes of campaign rallies [4]. Additional qualitative indicators involve monitoring reports from civil society organizations, tracking public protests, and analyzing public discourse on issues such as institutional trust, economic dissatisfaction, and the desire for change [5][4][6]. While international and domestic observer missions play a crucial role in documenting electoral legitimacy, their focus remains on evaluating the electoral environment rather than predicting vote shares [7][4][8]. Prediction markets and post-election qualitative analyses are also utilized for retrospective or speculative framing of voter sentiment in the absence of traditional polling data [5][9].
Sources (9)
  1. 12025 Guinea-Bissau general electionen.wikipedia.org
  2. 2Media and Electionsaceproject.org
  3. 32025 Guinea-Bissau general election | Detailed Pediadetailedpedia.com
  4. 4Guinea-Bissau Election: 12 Candidates and Portugal Impacttheportugalpost.com
  5. 5Guinea-Bissau Presidential Race Intensifies: Challenger and Incumbent Both Claim Victoryafric.news
  6. 6EXPLAINER – Guinea-Bissau votes in a test of democracyaa.com.tr
  7. 7PRELIMINARY STATEMENTau.int
  8. 8Guinea-Bissau - Observe West Africaobservewestafrica.org
  9. 9https://polymarket.copilot.markets/event/guinea-bissau-constitutional-referendum-20260723190646078/will-the-2026-guinea-bissau-constitutional-referendum-pass-20260723190646079polymarket.copilot.markets

10. What specific actions from the ECOWAS mediation mission, led by Senegal, could serve as catalysts to alter the election timeline or candidate eligibility before December 2026?

Lead Mediator AppointedSenegal in July 2026 [1]
Elections ScheduledDecember 6, 2026 [2]
Constitutional Referendum PlannedAugust 30, 2026 [3]
ECOWAS, led by Senegal, seeks to restore constitutional order. The ECOWAS mediation mission, under Senegal's leadership, is engaged in influencing Guinea-Bissau's political transition following a November 2025 coup and subsequent military-led transitional governance [2][4][3]. Senegal was formally appointed as the lead mediator in July 2026, receiving its mandate in August 2026 [1][2][5]. The primary objective of ECOWAS is to advocate for a more inclusive transition and the restoration of constitutional order within the nation [2][4][3].
ECOWAS pressures transitional authorities to adjust election processes. ECOWAS is actively pressuring the transitional authorities to potentially alter the election timeline or candidate eligibility ahead of the presidential and legislative elections, which are officially scheduled for December 6, 2026 [2][6][7]. Specific demands from ECOWAS include the release of political detainees and ensuring broad participation in the political process, moving beyond the current electoral framework [2][4][3]. Potential actions to facilitate these changes involve leveraging mediation to modify the constitutional referendum, slated for August 30, 2026, or compelling the junta to relax candidate eligibility criteria, which could allow previously excluded opposition figures, such as those from the PAIGC, to participate [3][6][8].
Sources (8)
  1. 1Senegal Begins ECOWAS Mediation Mission in Guinea-...wavn.org
  2. 2Ecowas appoints Senegal as mediator in Guinea-Bissauapanews.net
  3. 3ECOWAS move sparks backlash in Guinea-Bissau - Radar Africaradarafrica.com
  4. 4ECOWAS Pressures Military in Guinea-Bissau - More Afrikamaisafrika.com
  5. 5Senegal Begins Mediation Mission to Restore...wadr.org
  6. 6Guinea-Bissau election: Coup leaders confirm polls for 6 Decemberbbc.com
  7. 7Guinea-Bissau: Ninth and Tenth Reviews Under the Extended...elibrary.imf.org
  8. 8Guinea‑Bissau’s Military Junta Sets Dec. 6, 2026 Election Date After Coup - NuvaPulsenuvapulse.com

11. What Could Change the Odds

Key Catalysts

On November 23, 2025, Guinea-Bissau held presidential and legislative elections that were later annulled following a military coup on November 26, 2025 [1][2][3][4]. Although presidential elections were part of this reported event, no evidence of a presidential election occurring on November 23, 2025, exists in expert-curated databases such as the AP Elections repository [5][6][7]. The military junta, led by Major-General Horta Inta-a, seized election materials, destroyed servers, and arrested opposition figures including Fernando Dias da Costa and Domingos Simões Pereira [1][3][8]. Major-General Horta Inta-a was sworn in as transitional president on November 27, 2025 [1][3][8].
New elections have been scheduled for December 2026, following the coup and the failed 2025 election [9]. As of June 2026, opposition leader Domingos Simões Pereira remains under house arrest, raising international concerns regarding the credibility of future electoral processes [10].

Key Dates & Catalysts

  • Closes: November 23, 2025
Sources (10)
  1. 1Guinea-Bissau cannot complete presidential election,...reuters.com
  2. 2Election results | Guinea-Bissau | IPU Parline: global data on...data.ipu.org
  3. 3Guinea-Bissau's electoral commission says coup...aljazeera.com
  4. 42025 Guinea-Bissau general electionen.wikipedia.org
  5. 5AP Elections: Information & Services | The Associated Pressap.org
  6. 6APIntelligence | The Associated Pressap.org
  7. 7Interactive Graphics Archives | The Associated Pressap.org
  8. 8The Never-Ending Transition: When Uncertainty Becomes the Norm - PRIF BLOGblog.prif.org
  9. 9(PDF) Guinea-Bissau in parentheses: civil-military dynamics and electoral risk ahead of the December 2026 elections A political analysisacademia.edu
  10. 10Guinea-Bissau: Opposition leader house arrest raises stakesdw.com