Prediction markets: the hidden danger revealed by a blockchain expert

Prediction markets, popularised by platforms such as Polymarket and Kalshi, are growing rapidly, but they harbour major risks, particularly those linked to anonymity, manipulation and worrying ethical lapses.

When betting on the future becomes a global phenomenon

The principle behind prediction markets is simple: betting money on the outcome of a future event such as an election, an economic crisis or an international conflict… This model is based on contracts that function like binary bets. A question is posed and users buy a ‘yes’ or ‘no’ position. If the event occurs, those who placed the correct bet are paid out.

Jacob Boersma, blockchain expert: 

“With blockchain, it is possible to create smart contracts that automatically execute transactions when certain conditions are met.” 

Anonymity: a major risk that is difficult to contain

The main danger identified by Jacob Boersma concerns anonymity. Transactions on these platforms are often carried out in cryptocurrencies, which makes it considerably more difficult to identify participants.

“It is very difficult to know who is behind the bets,” explains the expert.

This lack of transparency opens the door to abuse, particularly the use of inside information. For example, shortly before the capture of Venezuelan President Nicolás Maduro, large sums were bet on a scenario predicting that he would be ousted from office before the end of January. Some experts suspect that inside information regarding this event was accessed.

In traditional financial markets, insider trading is severely punished. But in the world of prediction markets, the traceability of participants is so limited that it becomes extremely difficult to apply the same rules.

A worrying drift towards extreme scenarios

Beyond the financial risks, a darker dimension emerges. Jacob Boersma raises a disturbing possibility: that these markets could evolve into something akin to ‘assassination markets’.

The idea may seem extreme, but if a violent event becomes the subject of a bet, certain individuals might be tempted to provoke that event in order to profit from it. Terrorist attacks, targeted assassinations, geopolitical crises… when everything becomes monetisable, the temptation to turn a prediction into reality becomes a tangible threat.

“Sensational bets can encourage people to take action,” warns Boersma.

A silent influence on political decisions

Prediction markets do more than simply reflect expectations: they can also shape them.

According to Jacob Boersma, the signals sent by these markets can influence political and administrative decision-makers. If a particular scenario appears to be widely anticipated, some officials might adjust their decisions accordingly.

Accuracy sometimes surpassing that of opinion polls

 Despite this criticism, prediction markets also have advantages. In some cases, they prove surprisingly accurate, particularly during elections. Unlike opinion polls, where responses may be approximate or influenced by bias, prediction markets are based on a real financial commitment. Participants therefore have an incentive to be as accurate as possible.

However, this effectiveness depends on one key factor: the predictability of the event. For random events, such as the weather, their accuracy plummets.

Regulation still in its infancy

In Belgium, prediction markets are classified as online gambling, and the Polymarket platform has been blocked since early 2025.

The platforms, for their part, take a different view. They claim not to fall under the category of traditional gambling, but to offer analytical tools based on collective intelligence. A position that regulators do not share.

Prediction markets represent a fascinating innovation at the intersection of finance, technology and information. But this promise comes with considerable risks. Anonymity, manipulation, ethical lapses, political influence… these are all challenges that call into question their legitimacy and the need for regulation.