Prediction markets chase science forecasts—experts warn of distortions

Prediction markets like Polymarket and Kalshi are increasingly trading in questions that look like science questions: pandemics, climate extremes, even quantum decryption. But researchers and specialists say the crowd may track public sentiment—and sometimes a

For a while. the internet’s newest betting craze has looked less like a pastime and more like a side channel for science. In the span of a few months, prediction markets such as Polymarket and Kalshi have soared in popularity. And in many of their markets, the bets don’t just ask who will win a race. They ask what will happen to disease. which year will be hottest. and whether a quantum computer will soon be able to “break” the cryptocurrency Bitcoin.

The mechanics are simple enough to sound like a clean forecasting tool. In a prediction market, users bet on a future event by buying and selling shares tied to different outcomes. The price of each share is not set by expert opinion, and it’s not determined by the “house” odds. Instead. prices are driven by demand—an effort at turning collective belief about probability into something that moves as people trade.

Supporters point to a familiar idea: the “wisdom of crowds,” where large groups can outperform individual experts. Polymarket’s website makes the case that prediction markets can be more accurate than experts or polls because “economic incentives ensure market prices adjust to reflect true odds as more knowledgeable participants join.” But accuracy is not the only question. Researchers who study markets say the real challenge is what the prices are actually reflecting—and what can get warped in the process.

Richard Borghesi. who researches finance and prediction markets at the University of South Florida in Tampa. describes prediction markets as “potentially helpful forecasting supplements.” He says they can gauge how scientific information is received by the public. Yet he is firm about the limits: they are not “substitutes for models. peer review or expert judgement. ” and they become less informative when the people trading lack specialist knowledge on the subject.

Concerns about market integrity add another layer of doubt. There are growing worries about market manipulation and insider trading on Polymarket and Kalshi. In October last year. Norwegian officials who oversee the Nobel Peace Prize investigated a surge in bets for Venezuelan opposition leader Maria Corina Machado hours before she was awarded the prize.

That mix—fast-moving crowd estimates, uneven expertise, and the possibility of gaming—shows up sharply in science areas where probabilities are hard to pin down.

Disease outbreaks are one of the clearest battlegrounds.

When an outbreak of hantavirus was reported on a cruise ship in early May. a Polymarket market predicted a 19% probability of the World Health Organization (WHO) declaring a hantavirus pandemic this year. The probability sank after the initial shock. and by the time the article was published. the market sat at a probability of 5%. with about US$14 million in shares traded so far. A similar Kalshi market predicts a 7% chance of the WHO declaring a hantavirus outbreak a public-health emergency of international concern in 2026.

The market logic here is partly informed by public-facing science. Users in these markets do follow some scientific evidence: comment sections reference WHO updates and case numbers. But the benchmarks experts rely on are broader and more technical. Researchers often forecast disease spread using mathematical models and a variety of data. including hospital surveillance. genomic data and even school absences.

Even experts struggle to put a precise number on something as sweeping as a pandemic. Vaithi Arumugaswami. an infectious-disease researcher at the University of California. Los Angeles. says the chance of a global hantavirus outbreak “is very. very low.” He points to forecasting from the US Centers for Disease Control and Prevention. which suggests the virus’s risk to the US public is extremely low. He also notes what the WHO says: transmission between humans is uncommon.

Bill Hanage, an epidemiologist at Harvard University in Cambridge, Massachusetts, links the trading itself to another force—anxiety. He says the way users trade may be an effect of anxiety surrounding pandemics. which seems especially present since the COVID-19 pandemic. In that regard, Polymarket bets, he says, “tell you something about how the public feels.”.

When you move from disease to climate, the mood changes—but the debate doesn’t disappear.

Prediction markets are also buzzing around climate change, and some bets appear “reasonably in line with experts’ estimates,” says Zeke Hausfather, a climate scientist at the research organization Berkeley Earth in California.

One Polymarket market predicts a 34% chance of 2026 being the hottest year on record. and a 60% chance of it being the second. Kalshi similarly gives this year a 32% chance of being the hottest yet. Hausfather’s own real-time projections. based on data from the European Space Agency’s Earth-observation programme Copernicus. give a 28% chance of 2026 being the hottest year so far and a 67% chance of it being the second hottest.

The calendar is only getting hotter, according to institutions that track it. Last week, a report from the World Meteorological Organization warned that a record-breaking hot year is almost certain by 2030.

In other words: the markets may sometimes land close to expert expectations—at least on broad, headline-friendly outcomes.

And then there’s quantum computing, where the questions turn technical fast.

Polymarket users are placing bets on whether a quantum computer will soon be able to ‘break’ the cryptocurrency Bitcoin by deriving the private key associated with an existing Bitcoin address. In that market, the chance is priced at 3% for the end of 2026 and 16% for the end of 2027.

Scott Aaronson. a theoretical computer scientist at the University of Texas at Austin. says breakthrough progress this year has pushed forward the timeline for quantum computers cracking such keys. but it will still take time to build a system at the scale necessary to threaten cryptography. The timeframes posed by Polymarket, he says, are probably too optimistic. Still, he adds that some specialists think the feat could be possible in the next few years.

The obstacle list is long. Chloe Martindale. who researches post-quantum cryptography at the University of Bristol in the UK. says one unknown is how long it will take to overcome major obstacles that keep quantum computing from real-world use. She says such a breakthrough could happen this year—or “it could be in 30 years.”.

Borghesi puts a caution flag at the end of the chain: prediction markets shouldn’t be taken as “definitive evidence that a scientific risk is either serious or not serious.” Sometimes. he says. the market may only be reflecting short-term sentiment or the way a contract happens to be written. In his view. the value of these markets is highest when they are treated as one signal among many. not as a replacement for scientific expertise.

As Polymarket and Kalshi keep expanding into science-adjacent questions. the promise is obvious: probabilities that change as people trade. and a public-facing mirror for how uncertainty is felt. The warning is just as clear. In science. especially where data is incomplete and incentives move quickly. the crowd can offer useful information—but it can also measure the noise.

prediction markets Polymarket Kalshi science forecasting wisdom of crowds pandemics hantavirus World Health Organization climate change European Space Agency Copernicus World Meteorological Organization quantum computing post-quantum cryptography Bitcoin