The Complete Beginner's Guide to Prediction Markets
What contracts are, how prices become probabilities, and how to place your first trade on Kalshi or Polymarket.
What Is a Prediction Market?
A prediction market is a platform where you can buy and sell contracts based on whether a real-world event will happen or not.
Think of it like this: instead of betting on a sports team, you're trading on probability itself. A contract on a prediction market represents a question with a binary outcome — Yes or No — and its price directly reflects what the crowd thinks the probability is.
Example:
"Will the Federal Reserve cut interest rates at its June meeting?"
If this contract is trading at $0.72, the market collectively believes there is a 72% chance of a rate cut. You can buy the "Yes" side if you agree, or the "No" side if you disagree.
If you're right, your contract pays out $1.00. If you're wrong, it pays out $0.00.
How Contracts Work
Every prediction market contract follows the same basic structure:
| Element | What it means |
|---|---|
| Question | A specific, verifiable event with a clear resolution |
| Price | Expressed in cents (e.g. $0.65 = 65% implied probability) |
| Yes side | Pays $1 if the event happens |
| No side | Pays $1 if the event does NOT happen |
| Resolution date | The date the outcome is determined and contracts settle |
The price of Yes + the price of No always approximately equals $1.00 (minus a small platform fee). So if Yes is $0.65, No is approximately $0.35.
The Key Insight: Price = Probability
This is the most important concept in prediction markets and what makes them different from traditional betting.
When you look at a contract priced at $0.67:
- You're not just seeing odds
- You're seeing the collective wisdom of all traders — their aggregated estimate of the probability
- That price updates in real time as new information arrives
This is why financial analysts, journalists, and policymakers increasingly look at prediction market prices alongside traditional polls and forecasts. Markets aggregate information from thousands of participants — including some who have very good reasons to hold specific views.
Prediction Markets vs. Sports Betting: What's the Difference?
Many people come to prediction markets from a sports betting background. Here's how they compare:
| Sports Betting | Prediction Markets | |
|---|---|---|
| How you make money | Beating the bookmaker's line | Trading on probability vs. other traders |
| Who you're against | The house (bookmaker) | Other market participants |
| Fee structure | Hidden in the odds (vig/juice) | Explicit trading fee (~1-2%) |
| Sharp traders | Restricted or banned | Welcomed — they improve prices |
| Information value | Entertainment | Genuine forecasting signal |
| Can you exit early? | Sometimes, at a penalty | Yes — sell your position any time before resolution |
| Regulation | State gambling commissions | CFTC (as financial derivatives) |
The biggest practical difference: you can exit a prediction market position any time. If you buy Yes at $0.55 and the market moves to $0.72, you can sell for a profit without waiting for the event to resolve.
The Two Major Platforms
Kalshi
- Regulated by: CFTC (US federal regulator)
- Available in: All 50 US states
- Market types: Politics, economics, sports, crypto, weather
- Settlement: US dollars, direct bank transfer
- Best for: US-based traders who want a fully regulated, traditional finance experience
Polymarket
- Regulated by: CFTC (via QCEX acquisition, 2025)
- Available in: US + international
- Market types: Politics, crypto, economics, sports, global events
- Settlement: USDC stablecoin on Polygon blockchain
- Best for: Traders comfortable with crypto rails; largest volume and market selection globally
Your First Trade: Step by Step
Step 1: Choose a platform Sign up for Kalshi (simplest for US users) or Polymarket (larger market selection).
Step 2: Fund your account Kalshi: bank transfer or card (USD). Polymarket: deposit USDC (you'll need a crypto wallet like MetaMask).
Step 3: Find a market you have a view on Start with something you follow closely — a sport you watch, an economic indicator you track, a political race you're engaged with.
Step 4: Assess the probability Does the current price reflect your view? If the market says 60% and you think it's 75%, you have an edge. If you agree with 60%, there's no trade to make.
Step 5: Start small Your first few trades should be learning exercises, not profit attempts. Trade $20–50 while you understand how the mechanics work.
Step 6: Monitor and decide Watch your position. Did new information arrive? Has the price moved in your favour? You can sell early to lock in gains or cut losses at any point.
Common Beginner Mistakes
❌ Treating it like a sportsbook The mindset shift matters. You're not picking winners — you're assessing whether the market's implied probability is wrong. A team you love might be accurately priced at 30% — that's not a good bet at any odds.
❌ Ignoring the resolution criteria Every market has specific resolution criteria. "Will X happen?" can resolve differently than you expect if you haven't read the exact definition. Always read it before trading.
❌ Over-concentrating on one event Diversification matters in prediction markets just like in investing. A single unexpected event can move any market dramatically.
❌ Not using Prediction Markets Checking only one platform means you might miss better prices or arbitrage opportunities on the same event. Always compare before trading.
❌ Forgetting about fees Kalshi charges approximately 1-2% per trade. Polymarket charges a small taker fee. Factor these into your edge calculation — a 2% edge doesn't pay after fees.
Glossary of Key Terms
Binary contract — A contract that resolves to either $1 (Yes) or $0 (No).
Implied probability — The probability suggested by a contract's price. A $0.72 contract implies 72%.
Resolution — When the event happens (or doesn't) and contracts pay out.
Liquidity — How easy it is to buy or sell a contract without moving the price. High-volume markets have high liquidity.
Spread — The gap between the lowest ask (what sellers want) and highest bid (what buyers offer). Tighter spreads mean lower trading costs.
Arbitrage — When the same event is priced differently on two platforms, creating a risk-free profit opportunity. Prediction Markets highlights these automatically.
Market maker — A trader (or firm) that continuously posts buy and sell prices, providing liquidity. They earn the spread.
Position — Your current holding in a market. You can be long Yes, long No, or flat.
Edge — Your advantage over the market price. If you believe Yes is 75% and it's priced at 65%, you have a 10-point edge.
What to Read Next
- How to Read Probability Charts — Understanding price history and what it tells you
- Finding Arbitrage Opportunities — Using Prediction Markets's comparison to profit from platform discrepancies
- The 5 Best Market Categories for Beginners — Where to start and why
- Understanding Market Liquidity — Why some markets are easier to trade than others
- Prediction Markets vs. Stocks: A Trader's Comparison — For investors coming from equities
Predictboard aggregates real-time data from Kalshi and Polymarket. We're not a trading platform — we help you find the best prices and opportunities across both. [See live markets →]