62% Chance
How Prediction Markets Like Polymarket and Kalshi Really Work, Explained by a Sportsbook Trader
The screen says 62%. Should you buy it? Armando Acevedo spent 25 years setting the prices bettors play against. In plain English, with real numbers, he follows one beginner from her first look at a price to a tested trading plan, and shows you how the people who set prices for a living think.
- 22 chapters in five parts, about 270 pages
- Eight charts, worked examples on every page, a glossary, a formula sheet and an index
- A “Try this” exercise at the end of every chapter that costs nothing
- Every fee, rule and law checked as of October 20, 2026
Contents
Part I. The Idea
- 1. 62% of What?
- 2. The Price Is the Probability
- 3. Who’s on the Other Side?
- 4. The Fine Print Wins
- 5. From Wall Street to Your Phone
Part II. The Platforms and the First Trade
- 6. Kalshi: The Regulated One
- 7. Polymarket and Polymarket US
- 8. Who Can Use What
- 9. Ana’s First Trade
Part III. The Money
- 10. Every Fee, Explained
- 11. What You Need to Win
- 12. Your Own Number
- 13. Edge
Part IV. Thinking Like a Trader
- 14. Steal the Sportsbook’s Homework
- 15. How Much to Bet
- 16. When to Buy, When to Sell
- 17. Free Money That Isn’t
- 18. The Journal and the Closing Price
Part V. The Real World
- 19. What Everyone Trades, and Who Wins
- 20. Where You Might Have an Edge
- 21. Losing Without Being Wrong
- 22. Ana’s 30-Day Challenge
Plus an epilogue on where prediction markets are heading, and appendices: glossary, formula sheet, journal sheets, sources by chapter and an odds table.
About the author
Armando Acevedo is a sportsbook trader and author with 25 years of experience in the betting industry. His books explain pricing, probability, and risk in clear, practical terms.
He is also the author of The Sportsbook Trader, a two-volume course in sportsbook trading from the house side.
Questions people ask
Who is 62% Chance for?
Complete beginners who have seen Kalshi or Polymarket odds on TV or social media and want to understand them before risking money, and sports bettors curious about how prediction markets differ from sportsbooks.
Is it a get-rich guide?
No. It explains how prices, fees and the other side of the trade work, shows the data on who wins and loses, and teaches you to decide when not to trade. It never tells you what to buy.
Can I buy it in Mexico?
Yes. The Kindle edition is sold on Amazon.com.mx. The paperback and hardcover are printed in the US and ship to Mexico from Amazon.com.