How accurate are prediction markets when you compare their forecasts with what actually happened? Prediction market apps like Kalshi and Polymarket US turn traders' expectations into probabilities, offering a running estimate of who might win an election, take home a championship or collect a major award.
Of course, even a strong favorite can lose. And when traders back the eventual winner, that alone doesn't tell you whether the original probability was reasonable.
I compared nine resolved markets across politics, sports and pop culture, looking at historical prices alongside the final results. The examples show where traders' expectations lined up with reality, where the surprises came and why judging a forecast by one outcome can be misleading.
How Accurate Are Prediction Markets? The Short Answer
Prediction markets can be useful forecasting tools, but their prices represent probabilities rather than guarantees. An 80-cent contract losing doesn't automatically mean the forecast was inaccurate, since the opposite outcome still had a 20% implied chance.
Long story short, accuracy depends on available information, liquidity and how close an event is to resolution.
Keep reading: Understanding Liquidity vs. Accuracy at Prediction Markets: A Guide for Traders
What a Prediction Market Probability Actually Means
On a prediction market, a contract's price shows roughly how likely traders think an event is to happen.
For example, a Yes contract trading at $0.60 suggests a 60% chance of that outcome. If it happens, the contract pays $1, so you'd make $0.40 before fees. If it doesn't, the contract pays $0.
The higher the price, the more likely traders think the event is. But even an 80% chance isn't a sure thing. The other outcome still has a 20% chance, meaning you'd expect it to happen about one in five times across many similar events if those probabilities are accurate.
Here's how different contract prices translate into probabilities:
| Contract Price | Implied Probability | What It Suggests |
|---|---|---|
| $0.20 | 20% | Unlikely, but still possible |
| $0.50 | 50% | Neither outcome is favored |
| $0.80 | 80% | Strongly favored, but not guaranteed |
| $0.95 | 95% | Very likely, but not certain |
Remember: these percentages reflect traders' expectations, so fees, differences between buying and selling prices, and trading behavior can all affect how accurate they are
Prediction Market Accuracy Scorecard: 9 Resolved Markets
I chose nine popular markets fromKalshi where I could compare prices recorded before the events with what actually happened. Most prices are from the days leading up to the results, although the Knicks championship example comes from an earlier playoff round.
| 🗂️ Category | 📊 Market Prediction (Price, Platform, Date) | 🏁 What Happened | ✓ / ✗ |
|---|---|---|---|
| Politics | Donald Trump to win the 2024 presidential election: 59% on Kalshi, November 5, 2024 (morning ET) | Trump defeated Kamala Harris, winning 312 electoral votes. | ✓ |
| Politics | Republican candidate to win the 2024 national popular vote: 25% on Kalshi, using the last trade by 7 a.m. ET, November 5, 2024* | Trump won the popular vote despite being the less-favored outcome. | ✗ |
| Politics | James Talarico to win the Texas Democratic Senate primary: 77% on Kalshi, March 2, 2026 | Talarico defeated Jasmine Crockett in the March 3 primary. | ✓ |
| Sports | Seattle Seahawks to win Super Bowl LX: 68% on Kalshi, February 4, 2026 | Seattle defeated New England 29-13 on February 8. | ✓ |
| Sports | Michigan to win the men's NCAA basketball championship: 74% on Kalshi, April 6, 2026 | Michigan defeated UConn 69-63 that evening. | ✓ |
| Sports | New York Knicks to win the NBA championship: 5.1% on Kalshi, May 1, 2026 | New York won the championship in June, defeating San Antonio 4-1 in the NBA Finals. | ✗ |
| Pop Culture | One Battle After Another to win Best Picture: 76% on Kalshi, March 14, 2026 | The film won Best Picture at the March 15 Academy Awards. | ✓ |
| Pop Culture | One Battle After Another to win Best Cinematography: 77% on Kalshi, March 15, 2026, before the ceremony | Sinners won Best Cinematography. | ✗ |
| Pop Culture | “Golden” to win Grammy Song of the Year: 72% on Kalshi, January 29, 2026 | Billie Eilish's “WILDFLOWER” won on February 1. | ✗ |
The ✓/✗ column shows whether the market favored the eventual winner, but that alone doesn't establish whether its probability was accurate.
*The 25% popular-vote figure comes from an independent review of Kalshi's historical trades. It reflects the last recorded price before 7 a.m. ET on Election Day, rather than the market's average price throughout the day.
Where Prediction Market Predictions Got It Right
Some of the favorites in the scorecard had good reasons to be favored even before the results came in.
- James Talarico's Texas primary victory: On March 2, Kalshi gave Talarico a 77% chance of winning, even though a University of Texas poll had Crockett leading 56% to 44%. Talarico went on to win, although it's hard to say exactly why traders were more confident in him than that poll suggested.
- Michigan's NCAA championship: Michigan was a 74% favorite against UConn on April 6, and its performance leading up to the game helped explain why. The Wolverines were a No. 1 seed coming off a strong March Madness run, and they finished the job with a 69-63 victory.
- One Battle After Another winning Best Picture: The film had already picked up major awards at the Golden Globes and Critics Choice Awards, so its 76% chance of winning Best Picture on Kalshi wasn't surprising. It went on to take home the Oscar the following day.
Ultimately, all three favorites went on to win, and there was a lot of information supporting their chances beforehand. Still, getting the winner right doesn't tell us whether the exact percentages were accurate
Where the Markets Missed, and Why an Upset Isn’t a Failure
Just because a market favors one outcome doesn't mean its prediction was unreasonable when something else happens. A few examples from the scorecard show why.
On Election Day 2024, Kalshi gave Trump a 59% chance of winning the presidency but just a 25% chance of winning the popular vote. He won both. Does that mean the market got it wrong? Not necessarily. If you looked at hundreds of events given a 25% chance, you'd expect roughly one in four to happen if those predictions were accurate.
The Knicks were even bigger underdogs, with just a 5.1% chance of winning the 2026 NBA title on May 1. They eventually became champions but, at the time, they still had a lot of playoff series to win. At the Oscars, One Battle After Another was a 77% favorite for Best Cinematography, yet Sinners took home the award.
What does that mean? It means I wouldn't call any of these predictions inaccurate based on the results alone. Markets can get their prices wrong because of outdated information, limited trading or traders following the crowd, but there's no evidence those problems caused these particular surprises.
So how can you tell when a market is consistently getting its probabilities wrong? You need to compare prices with a much larger number of results. For instance, if contracts priced at 10 cents keep winning less than 10% of the time, traders may be overestimating those outcomes' chances.
That's the kind of pattern researchers found in a 2026 CESifo study covering more than 300,000 Kalshi contracts. Low-priced contracts won less often than their prices suggested, a tendency known as favorite-longshot bias. Unlike a single upset, repeated results like these can show where market prices consistently miss the mark.
How Accurate Are Prediction Markets Compared to Polls and Experts?
Of course, traders aren't the only ones trying to predict what happens next. Polls and expert forecasts can offer another perspective, especially when their predictions don't match what the markets are saying.
Markets can react quickly to breaking news as traders adjust prices, polls capture voter preferences at a particular moment (with margins of error and sampling uncertainty to consider), and experts and forecasting models bring historical context and statistical analysis that market prices might overlook.
There's also research suggesting that looking at more than one type of forecast can give you a better picture. In a 2019 study*, researchers looked at predictions for 113 political and international events. They compared prediction market prices with forecasts made by individuals and found that combining those individual forecasts was at least as accurate as the markets. When they combined both methods, the predictions were even more accurate.
*The study didn't compare prediction markets directly with traditional election polls, so it doesn't tell us whether markets are better at predicting election results. It also wasn't a direct test of today's US prediction market platforms.
Want to keep reading? Our2026 midterm prediction markets vs. polls comparison shows where forecasts agree and where they differ in individual races.
What Makes Prediction Market Accuracy Better or Worse
The question now is: why are some prediction markets better at predicting outcomes than others? A lot comes down to five factors:
| Factor | How It Affects Prediction Market Accuracy |
|---|---|
| Available information | The more reliable information traders have, the better they can judge an outcome's chances. Polls, statistics and official announcements can all help, while a lack of information makes predictions harder. |
| Time until resolution | There's usually less uncertainty as an event gets closer. Predicting who will win a championship months in advance, for example, is harder than assessing a matchup on game day. |
| Liquidity and trading volume | When there are lots of buyers and sellers, a single small trade is less likely to move the price significantly. More trading activity can help, but it doesn't guarantee accurate predictions. |
| Breaking news | An unexpected injury, a candidate dropping out or another major announcement can change the outlook quickly. Markets with fewer active traders may take longer to catch up. |
| Market structure | Platforms don't all determine prices the same way. Kalshi and Polymarket US use order books, where buyers and sellers post the prices they're willing to trade at. Other platforms may use automated pricing systems. |
Liquidity is especially worth paying attention to if you're thinking about trading. Say a contract last sold for 75 cents. That doesn't mean you can necessarily buy as many contracts as you want at that price. If there aren't enough sellers offering 75 cents, you might have to pay more.
Kalshi's own research backs up some of these points. In an August 2026 study, the exchange found that its predictions usually became more accurate as events got closer, especially in markets with more traders and trading activity. Of course, it's worth keeping in mind that these findings come from Kalshi itself.
How to Use Prediction Market Predictions Wisely
I think prediction market prices are most useful when you compare them with other available information rather than taking them at face value.
Start with Kalshi and Polymarket US when both offer contracts on the same event. Check their prices, resolution rules, fees and liquidity before drawing comparisons. Similar contract names don't always mean identical settlement conditions.
It's also worth watching how prices change. If a candidate jumps from 45% to 70% after a major announcement, look into what prompted the move. A price that's held steady for months tells a different story.
Also think about what's still unknown. How much time is left before resolution? Could new information change the outcome? Even a 95-cent contract can settle at zero.
And if you decide to trade, remember that event contracts carry real financial risk, including the possibility of losing your entire position.
Where to Follow Prediction Markets Yourself
Kalshi and Polymarket US are CFTC-regulated exchanges where eligible US users can follow and trade event contracts.
- Kalshi: Offers markets covering politics, sports, economics, entertainment and other events.
- Polymarket US: Offers event contracts through its US-regulated exchange, separate from Polymarket International.
| 🔮 Platform | 🎁 Welcome Offer | 🏷️ Promo Code |
|---|---|---|
| Kalshi | Trade $25, Get $55! | ACTION55 |
| Polymarket US | Deposit $10, Get a $25 Trading Bonus! | ACTION |
Both have age, identity and geographic eligibility requirements. Contract availability varies by jurisdiction, and qualifying for a promotion doesn't necessarily mean you can access every market.
How Accurate Are Prediction Markets FAQs
Has a prediction market ever been manipulated?
Yes. In July 2026, the CFTC found that former Congressman George Santos manipulated a Kalshi market about his State of the Union attendance. He made misleading public statements that moved prices in his favor. This shows how markets with fewer active traders can be easier to influence.
Do prediction markets get more accurate closer to the event?
Usually, yes. As an event gets closer, more information becomes available, helping traders make better predictions. Just remember last-minute surprises can still change everything.
Why do Kalshi and Polymarket sometimes show different prices for the same event?
Kalshi and Polymarket US have different traders, fees and levels of trading activity, so their prices won't always match. It's also worth checking the rules, since two contracts that read similar might settle differently.
What is calibration in prediction markets?
Calibration is a way to measure how reliable predictions are over time. For example, if events given a 70% chance happen roughly 70% of the time, those predictions are well calibrated.
Can prediction market probabilities change my own forecast?
Absolutely. Market prices can give you another perspective, especially when traders see an outcome differently than you do. If there's a big gap, it's worth checking the available information to understand why.
Sources
- Research: 2019 study on prediction markets and individual forecasts, 2026 CESifo study on Kalshi pricing, Kalshi's August 2026 calibration study.
- Historical prediction market prices: 2024 popular-vote market audit, Texas Democratic Senate primary, Super Bowl LX, Michigan's NCAA championship, Knicks NBA championship, Oscars Best Picture, Oscars Best Cinematography, Grammy Song of the Year.
- Regulatory information: CFTC's July 2026 George Santos enforcement action, Kalshi's regulatory status, CFTC filings for Polymarket US/QCEX.
