Priorbook · About
No jargon, start to finish. What problem this solves, what exists today, and where it’s headed.
Prediction markets are websites — Kalshi, Polymarket — where people bet real money on yes/no questions: will the Fed cut rates, will a given bill pass, will Bitcoin cross some price. The price of a bet reflects what the crowd currently thinks the odds are. Priorbook is a tool for people who trade on those sites.
A live cross-venue comparison tool. The /markets page pulls real, current prices directly from Kalshi and Polymarket, groups them by real-world topic (Fed decisions, Bitcoin price, elections, and so on), and shows both venues side by side so you can actually compare them — instead of opening two separate apps and holding the numbers in your head.
That’s the honest, literal value today: convenience and a clean side-by-side view. It doesn’t yet tell you what anything is actually worth — just what each venue currently charges.
Most existing tools in this space are arbitrage scanners — they just tell you “Kalshi says 34¢, Polymarket says 38¢, buy the cheap one.” That edge is shrinking fast as more bots compete for the same small gaps; funding both venues and fees eat most of what’s left. Priorbook is betting on something different: instead of comparing two venues to each other, figure out what a bet is actually worth using real-world evidence, then flag whenever a venue drifts away from that. Research instead of a race for pennies.
This is the plan for calculating what a bet is really worth. Five real inputs, blended into one number:
Live cross-venue price
Kalshi, Polymarket & adjacents, sub-second
Polling & expert forecasts
Public polling, forecaster panels
Historical base rates
Outcome distributions since 2014
News & NLP sentiment
Realtime ingest, entity-linked events
Wallet / smart-money flow
Opt-in wallet graph, fund-grade sizing
Blend all five, compare the result to what each venue is charging — a big gap means a real, evidence-backed mispricing, not just noise. (Exact weights aren’t published — the layers are the point, not the recipe.) See the full methodology and a worked example.
Prediction markets are a genuinely new, fast-growing asset class — Kalshi and Polymarket together are worth billions, and serious money is starting to move in as regulation clarifies. As that happens, that money will want a real research tool, not just a scanner. The goal is to become the trusted pricing layer for that category before anyone else claims it — the screen a serious trader opens before they click a button, the way Bloomberg is for bonds and equities.
Honestly: the product is still thin. Most of what makes Priorbook worth using long-term — the fair-value model, alerts, backtesting — doesn’t exist yet. Opening the doors wide now would mean a flood of people showing up to a half-built tool and bouncing. Keeping the cohort small means the people who do join are talking directly to the person building it, and their feedback actually shapes what gets built next — not a form letter, an actual say.
Right now
As it grows
That’s the whole picture. If it’s for you —
Prefer email? Reach us at edgemarkhq@gmail.com