Where our numbers come from.

Where the data comes from

• Polymarket: its public market data: events, outcome prices, 24-hour volume, order books and price history.
• Kalshi: its public trading API: events, markets, prices, volume and price history.

We don’t buy data from third parties and we don’t edit prices. When a platform’s data is briefly unavailable, a page shows the last prices we received.

How fresh it is

• Prices on our pages are at most about a minute old; the live charts on the home page update in your browser.
• The market-wide snapshot behind trends and dashboards refreshes every 15 minutes.
• The resolution calendar is rebuilt every day.

Prices and probabilities

A share or contract pays $1 if its outcome happens, so a price of 64¢ reads as a 64% implied probability. For an event with several outcomes we show each outcome’s Yes price, most likely first. Moves over 24 hours are in percentage points.

Volume is counted the way each platform reports it: US dollars (USDC) on Polymarket, contracts on Kalshi, each worth up to $1.

Price gaps between platforms

Compare and the spread scanner match the same outcome on both platforms: automatically, by event and outcome, plus pairs our team adds by hand. The gap is the difference between the two prices in percentage points. The scanner also takes off taker fees: Kalshi’s 7% × P × (1 − P) per contract, rounded up to the cent, and none on most Polymarket markets. Two markets with the same title can still resolve under different rules, so read both before acting on a gap.

Analyst picks

Each pick is published with the outcome, the odds at the time and the reasoning. When the market resolves, it is graded Won, Lost or Void, and graded picks stay on the record.

News

Stories come from publishers’ RSS feeds and from Google News searches for Polymarket, Kalshi and prediction markets. Each one shows the publisher’s own headline and summary, links to the original article and sits next to the live odds of its topic. Stories that come without a summary of their own are left out.

The AI assistant

The assistant answers with an AI model that is given the live odds of the market you ask about. It can be wrong: check a market’s rules on the platform before you trade.

Independence

PredictDesk is not affiliated with Polymarket or Kalshi, and nothing here is financial advice. See the risk disclosure and our terms. The words used here are explained in the glossary.