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Markets & Finance30 Oct 2026 · about 7 min

Prediction markets flop on recent elections

The brief

Prediction markets are trading venues where participants buy and sell contracts tied to future events, such as election results. The market price is commonly interpreted as the probability of an outcome. If a contract pays one unit when a candidate wins, a price near 80 cents suggests roughly an 80% chance. This makes trades a continuously updated forecast rather than a single poll. The mechanism depends on participants acting on information, beliefs, or analysis. Buying pushes a contract’s price higher, while selling pushes it lower. In theory, competition brings different views together in one number. For Brazil, Kalshi and Polymarket prices gave Flávio Bolsonaro a 4-in-5 chance, creating a strong market signal before he lost. The Brazil result shows why the concept matters. A market can produce a clear forecast and still be wrong. Kalshi has promoted market accuracy to institutional investors, so repeated misses could weaken confidence in using these prices for decisions or as hedges against political risk.

01

What are prediction markets, and how do they use trades to forecast election outcomes?

Prediction markets are trading venues where participants buy and sell contracts tied to future events, such as election results. The market price is commonly interpreted as the probability of an outcome. If a contract pays one unit when a candidate wins, a price near 80 cents suggests roughly an 80% chance. This makes trades a continuously updated forecast rather than a single poll.

The mechanism depends on participants acting on information, beliefs, or analysis. Buying pushes a contract’s price higher, while selling pushes it lower. In theory, competition brings different views together in one number. For Brazil, Kalshi and Polymarket prices gave Flávio Bolsonaro a 4-in-5 chance, creating a strong market signal before he lost.

The Brazil result shows why the concept matters. A market can produce a clear forecast and still be wrong. Kalshi has promoted market accuracy to institutional investors, so repeated misses could weaken confidence in using these prices for decisions or as hedges against political risk.

02

Which elections did Kalshi and Polymarket get wrong, and how confident were they in their forecasts?

Kalshi and Polymarket were wrong in Brazil, Israel, and Serbia, according to the article. In Brazil, both platforms gave conservative candidate Flávio Bolsonaro a 4-in-5 chance of winning. He lost to the progressive incumbent. That was the clearest numerical miss described.

The markets also overrated Netanyahu’s challenger in Israel. The article does not give a precise percentage for that forecast, but says the race remained too close to call. In Serbia, Kalshi gave the heavily favored incumbent strongman 75% odds as late as election day. He nevertheless lost.

These errors matter because the platforms present themselves as useful sources of information about political outcomes. Kalshi has specifically highlighted its accuracy to attract institutional investors. Three prominent misses in one week create a serious challenge to that sales pitch, especially when investors may use prices to guide trades in currencies, stocks, or political-risk hedges.

03

What happens to traders and investors when a prediction market gives a high-probability forecast that turns out to be wrong?

A high-probability forecast can shape real financial decisions. Traders may buy assets, sell protection, or position portfolios around the expected political result. If that result fails, those trades can lose money. The probability was never a guarantee, but the damage can be larger when the forecast appears especially confident.

Brazil provides the article’s clearest example. Kalshi and Polymarket gave Flávio Bolsonaro a 4-in-5 chance of winning. He lost to the progressive incumbent. The article says anyone who traded Brazil’s currency and stocks based on that expectation was cost by the mistake. The market signal therefore affected more than a prediction score.

The broader consequence is reputational and financial. Kalshi has promoted its market accuracy to institutional investors. When a hedge fails, investors may absorb trading losses while still paying to access or act on the information. As the article puts it, a hedge that does not work is both useless and expensive.

04

Why might hedge funds and other institutional investors use prediction markets as hedges against global political risk?

Institutional investors may use prediction markets because political outcomes can affect financial markets. A market price offers a compact, continuously changing estimate of an election result. That can help a hedge fund adjust exposure before uncertainty becomes a confirmed event. The article describes this appeal as protection against global risk.

The mechanism is straightforward. If traders expect a political change, they may alter positions in currencies, stocks, or other assets. A prediction-market price can serve as one input for that decision. Kalshi has promoted the accuracy of its markets to win institutional investors, suggesting that reliable forecasts could complement broader risk-management strategies.

But the week’s results expose the danger. Kalshi and Polymarket strongly favored Flávio Bolsonaro, yet he lost. Kalshi also gave Serbia’s incumbent 75% odds on election day, and the incumbent lost. These failures show that a prediction market cannot automatically function as a dependable hedge. Investors need to test its track record and compare it with other information.

05

How can suspicious bets affect confidence in a prediction market, and why might they lead to an investigation?

Suspicious bets can weaken trust in a prediction market because prices are supposed to reflect genuine trading judgments. If unusual activity appears to push prices toward an outcome, observers may question whether the market is measuring information or being distorted. That uncertainty can make investors less willing to rely on the price.

The article connects this issue to Israel. The markets overrated Netanyahu’s challenger, while the race remained too close to call. Separately, a series of suspicious bets elicited an investigation by Polymarket. An investigation can examine the trading activity and determine whether it reflected ordinary speculation or something that threatened the market’s integrity.

The immediate effect is uncertainty about the forecast and the platform’s controls. Even before an investigation reaches a conclusion, suspicious activity can damage confidence among traders and potential institutional users. The incident matters especially because these platforms present themselves as information tools and, in Kalshi’s case, as possible hedges against global political risk.

06

What other sources of election information—such as polls, expert forecasts, or local reporting—can investors compare with prediction-market prices?

Prediction-market prices are only one source of election information. Investors can compare them with polls, polling averages, expert forecasts, historical voting patterns, and reporting from journalists close to the campaign. Official election authorities become important as voting and counting proceed. These sources can expose a market price that looks unusually confident or isolated.

The comparison works by looking for agreement and explaining disagreement. If markets and polls point in the same direction, confidence may rise, though no forecast becomes certain. If prices diverge sharply from local reporting or expert analysis, investors can investigate the reasons before trading currencies or stocks. Local information may also identify developments that broad, automated prices miss.

The article gives investors a reason to make these comparisons. Kalshi and Polymarket strongly favored Flávio Bolsonaro, but he lost. Kalshi gave Serbia’s incumbent 75% odds on election day, yet he also lost. Those misses show why market prices should be treated as one input, not a complete information system.

07

What does an 80% probability actually mean, and why can an event with that probability still fail to happen?

An 80% probability expresses likelihood, not certainty. If the same type of situation could be repeated many times under comparable conditions, an accurately calibrated 80% forecast would be right about eight times out of ten. It does not promise that the favored event will happen in the particular election being watched.

That leaves a 20% chance for the opposite result. In the article, Kalshi and Polymarket gave Flávio Bolsonaro a 4-in-5 chance of winning Brazil’s election. A 4-in-5 chance is 80%, but he lost to the progressive incumbent. The outcome therefore fits within the forecast’s stated uncertainty, even though it was a costly miss for traders.

The problem arises when people treat probability as certainty. High odds can encourage large trades in currencies, stocks, or other assets. If the less likely outcome occurs, those positions can lose money. The Brazil result shows why investors must distinguish a strong forecast from a guaranteed outcome.

This brief was written by AI from the original reporting and checked by other models. Names, figures and quotes come from the source; read it for full context.

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