Hey Product Hunt! I'm Sebastian, I'm 15 and a high school freshman, and I built Ledge by myself using AI tools. I built it because I kept making predictions with my friends and there was never any record. Someone calls a game, an election, a culture moment, it happens exactly like they said, and two days later nobody remembers. I wanted a place that keeps score. Ledge is a free social prediction market for sports, politics, and culture. No real money ever. You get 1,000 credits on signup and 500 every day just for showing up. Under the hood it runs a CPMM so odds shift dynamically as bets come in, same mechanism Polymarket uses. Your calibration score is a Brier score that measures how accurate your probability estimates are, not just whether you won. The part I'm most proud of is Circles. Private groups where you and your friends bet against each other on literally anything. Your circle, your rules. Honest truth: this is my first real launch and I have a small number of users so far. This is my first real push to get people in the door. Would love to hear what you think. What would make you actually open this every day?

Ledge

Prove you called it — free social prediction market

Prove you called it — free social prediction market