Prediction market platforms: Illegal in France and potentially risky to users

The current popularity of prediction markets peaked during the 2024 US presidential election. Polymarket recorded a record volume of $3.6 billion on the electoral market and correctly predicted Donald Trump's victory, unlike several traditional statistical models. 

Today, some analysts and media outlets believe that Polymarket has become a reliable political analysis tool that complements opinion polls in measuring electoral trends and shifts in public opinion for political or journalistic purposes.

What is a prediction market?

Each prediction market is defined by:

1. A specific event with a binary "YES"/"NO" outcome (e.g. election result);

2. A clear and public resolution criterion based on a predetermined reference source (e.g. a recognised media outlet);

3. A defined time horizon, corresponding to the closing date and resolution of the contract (example: closing after one month).

The price of a contract results from the interaction of participants' positions and can be interpreted as an aggregate probability of the event occurring. 

Because of this mechanism, prediction markets resemble both betting platforms (allowing 24/7 wagering on on binary multi-event questions) and specialised financial products, due to their structure as event contracts and the possibility of reselling a position before the underlying event is resolved.

What is the economic weight of prediction market? 

Between January and October 2025, cumulative transaction volumes on the world's leading platforms exceeded £27.9 billion, with a weekly peak of over £2.3 billion in October. Their cumulative revenues are estimated at £2 billion by Citizen. Direct or indirect transaction fees constitute the main source of revenue for most prediction markets.

Who are the main players ?

In 2025, prediction markets remained dominated primarily by two players: Polymarket and Kalshi. Other operators remain marginal in terms of both reputation and volume.

What are the risks of addiction? 

The marketing of prediction market platforms aims to attract a new demographic that has previously been uninterested in traditional casino games and sports betting, and which views these platforms as an investment option. This perception of the "prediction market" as a form of "investment" reinforces an illusion of competence: the more competent users believe themselves to be, the more they play and the more addicted they become. Media coverage of large winnings generated by prediction markets, such as the "dream" possibility of making "easy" gains as with crypto trading, reinforces this illusion in the player, who becomes someone who "predicts the news better than others". 

The illusion of prediction markets as an "investment" is also reinforced by the illusion of being able to make "easy" gains, as with crypto trading.

Prediction markets have several addictive features that are amplified by the fact that, unlike legal gambling sites, they offer no protection: platforms are open 24 hours a day, there are no built-in betting limits other than the amounts wagered, no time limits, no identity checks to verify age, etc. The combination of visibility, accessibility and virality specific to this type of platform creates a significant addictive loop. 

Beyond the risks of addiction, other risks related to market or opinion manipulation may encourage harmful actions. Indeed, when a player can bet on an event and influence its probability, the market creates a financial incentive to cause or accelerate negative outcomes such as performance sabotage in sport or violent actions in geopolitics. 

What legal framework ? 

Given their popularity and the risks incurred by users, prediction markets are attracting growing interest from regulators around the world. The hybrid nature of these markets explains the varied approaches taken by regulators worldwide.

In France, in November 2024, the ANJ considered that the services offered by Polymarket could be regarded as unauthorised gambling and games of chance. It therefore approached the Panamanian publisher, which implemented a geoblocking system to prevent any betting from France. Kalshi has also implemented such a system. 

Germany, Belgium, Romania, Switzerland, the Netherlands, Poland, Greece, Cyprus, Ukraine and Portugal have blocked access to Polymarket, arguing that the platform offers gambling services without the required licence.

Outside Europe:

• In the United States, Polymarket was authorised by the CFTC (Commodity Futures Trading Commission) to offer betting to US residents in November 2025. The offer had previously been limited since 2022. The Nevada Gaming Control Board has just taken Polymarket to court, arguing that its prediction markets constitute illegal gambling and should be blocked.

• In Australia, the local regulator blacklisted Polymarket on 14 August 2025.

• In Colombia, in September 2025, the regulator asked internet service providers to block Polymarket.