Reading this market
The quote is much tighter than the market actually is
The spread on screen describes the first contract. At a size worth trading you walk down the book and pay for each level, so this costs several times what it appears to. A tight quote on a thin book is a worse market to trade than a wider quote on a deep one.
Quoted 0.70 points, but 1.81 points round trip at 10,000 contracts · Effective spread
Every line above is derived from a figure on this page rather than from a view about the outcome. None of it says what will happen, and none of it is advice.
Price history is on the paid plans. Both venues publish where a market traded, and we fetch it — so the line itself is not something only we have. What is ours is the book behind it: the depth at each level, the spread as it stood, what could actually have been filled. No venue publishes that and none of it can be fetched afterwards, so it exists only for the markets we were recording at the time.
How this contract resolves: the criteria as the venue published them, who settles it, and what in the wording would change what a position is worth.
Both venues publish resolution rules and neither shows you what is ambiguous in them. Recorded for every open market on Polymarket and Kalshi.
What each plan includes →The quoted spread describes the first contract. Everything after it comes from further down the book. How to read this.
| Size | Buy at | Sell at | Round trip | Fillable |
|---|---|---|---|---|
| 100 | 0.0235 | 0.0150 | 0.85pt | 100 |
| 500 | 0.0239 | 0.0150 | 0.89pt | 500 |
Priced by walking the recorded book, so a size the book cannot fill shows what it could fill rather than a figure extrapolated past the last level. Fees are not included: this is the cost of the book, not of the venue. Book recorded 2026-09-30 00:30.
You are seeing the first 2 sizes. The curve bends above them, which is the only part worth reading: a book can look tight at 100 contracts and cost several times as much at 10,000.
This book fills 10,000 contracts on both sides. Trader prices every size up to that, and says how far the cost has moved from the quote.
What each plan includes →Price history is on the paid plans. This is the shortest window, so you can see what it is: Trader reads back 30 days and Desk 90.
Neither venue publishes historic prices, so this exists only because it was recorded while it happened. It cannot be bought or backfilled later.
What each plan includes →