YKB

The social layer for fans that prediction markets are missing

SR005Founded 20243 peopleLos Angeles, United States of America

ykb.app/ ↗X ↗See on the Idea Map AI momentum

About

Speculation is becoming how people engage with culture. Betting & prediction markets are exploding. But they’re built for gamblers, not fans. Our unlock = Receipts: interactive prompts generated by our agent when news breaks. Fans react, predict, & compete together. 1M+ Receipts created since NFL beta began in September. 140k+ Receipts created in the last week. Starts in sports, expands to all areas of culture. We believe tapping into this fan energy around takes & predictions will bring speculation beyond just gamblers, to a billion people.

From their website

as of Jun 7, 2026ykb.app ↗

Consumer AppFree

YKB is a social app that lets sports fans share their takes, track them as receipts, and compare opinions with friends. It emphasizes a receipts-based, predictive engagement around who knows ball. The app is positioned as a new way for fans to interact and discuss sports topics.

Users provide predictions on daily prompts about sports topics, which are scored based on accuracy. The app records and displays receipts of past takes to show how predictions fared, enabling discussion and comparison with others. It aggregates user takes, ties them to receipts, and surfaces a belief-tracking experience around sports knowledge.

Who it’s for: Sports fans who want to publicly share and compare their takes on games and players, and who value documenting past predictions as receipts for accountability and discussion.

Features

daily prompts for sports topics
scores based on prediction accuracy
receipts of past takes to show outcomes
social comparison with friends
clean, easy-to-use interface
discussion and insights from takes

app store presence, user ratings, ongoing feature updates and bug fixes)

Founders · 2

David LuCEO, Co-founder

Harvard

Harvard CS dropout; co-founded Airr - social podcast app, 100k+ users; Built products used by ESPN & The Athletic. Now cofounder of YKB, building the prediction experience fans actually want.

LinkedIn ↗

Sam RukeyserCofounder

Harvard

Harvard dropout; cofounded Airr, grew to 100k+ users without spending a cent on marketing; built products used by ESPN & The Athletic; growth is play. With YKB, we're building the prediction platform fans actually want. Was headed for intelligence work before deciding startups are a lot more fun. Started selling at 9 — zip-code hats, then web design, then hoverboards, all before 18. Love riding bicycles (rode one across America). New Yorker whose family has had Giants season tickets since the 70s.

LinkedIn ↗