About, disclosures and privacy.
Short, because there isn't much to say. Nothing on this site is advice and nothing on it places orders.
What this is
VenueGap reads public market data from two prediction-market exchanges, Kalshi and Polymarket, finds the events both of them list, matches each outcome to its twin on the other venue, and shows where the two prices disagree. It refreshes every 45 seconds. It is not affiliated with, endorsed by, or connected to either exchange.
How the numbers are made
- Games are matched by league, team codes and date; multi-outcome markets (nominations, futures, Fed meetings) by outcome name. A match that cannot be made with confidence is dropped rather than guessed.
- Polymarket prices come from its live order book; Kalshi prices from its public API. Prices shown are mid-market unless labeled bid and ask.
- The gap is the Kalshi mid minus the Polymarket mid, in percentage points of probability.
- The edge is what would be left from $1 after buying one side on one venue and the other side on the other, both at the ask, minus each venue's published taker fee. It ignores order size, slippage, withdrawal costs and the time it takes to move money. Treat it as a description of prices, not an instruction.
- Markets with no two-sided book or a spread wider than 10¢, and favorites priced at 95¢ or more, are hidden by default because their gaps are rounding, not disagreement.
How the site makes money
Affiliate disclosure. Links from this site to Kalshi and Polymarket may be referral links. If you sign up or trade through one, the exchange may pay this site a referral fee or a share of trading fees. That never changes the prices shown, the order of anything on the page, or whether an event appears. Both exchanges' referral terms forbid us from referring ourselves, and we don't.
The site may also apply to the exchanges' builder or grant programs. It does not sell picks, signals, or access to anyone's trading account.
What we store about you
- No cookies, no tracking pixels, no third-party analytics. Your browser keeps your own preferences (theme, filters, watchlist) in its local storage; that data never leaves your device.
- Usage counts. The site records that a page was viewed, an event was expanded, or an outbound link was clicked, with the category and, for views, the referring site. No IP address, user id, or fingerprint is stored with these events.
- Email list. If you ask for the morning report, we store your email address, a random token used for your confirm and unsubscribe links, the status of your subscription, and timestamps. Nothing is sent until you click the confirmation link. Every email carries a one-click unsubscribe. An unsubscribed address is kept only as a suppression record so it is never emailed again. Emails are delivered through Resend, which processes the address to deliver the message.
- Rate limiting. To stop abuse, the server keeps a short-lived, in-memory count of requests per connection address. It is not written to disk.
- Where it lives. On the server that runs the site and in a daily backup. To have your address removed entirely rather than suppressed, email the address in the footer.
Data and reuse
Everything on the screener is available as JSON at /api, free, with attribution. The underlying prices belong to the exchanges and to the people trading on them; this site claims nothing but the matching and the arithmetic.
Contact
Corrections, a market that looks mis-matched, a league you want covered: hello@venuegap.com.
Last updated September 2026.