Prediction Market Data in Google Sheets and Excel (2026)

Can you get prediction market data into a spreadsheet?

Yes. Prediction market prices are just numbers from a URL, and both big US-accessible venues publish them for free. Polymarket's Gamma API lists markets with their prices and volume, and Kalshi's Trade API lists markets with their Yes bid and ask. The only catch is format: both return JSON, and each spreadsheet handles JSON differently.

How do you get Polymarket and Kalshi prices into Google Sheets?

Google's IMPORTDATA function imports CSV and TSV only, so it cannot read these JSON APIs. Instead, add two custom functions with Apps Script. In your sheet, open Extensions > Apps Script, paste this, and save:

/**
 * Top Polymarket markets by 24-hour volume.
 * In a cell: =POLYMARKET_TOP(10)
 * @customfunction
 */
function POLYMARKET_TOP(limit) {
  const url = 'https://gamma-api.polymarket.com/markets?active=true&closed=false&order=volume24hr&ascending=false&limit=' + (limit || 10);
  const markets = JSON.parse(UrlFetchApp.fetch(url, { muteHttpExceptions: true }).getContentText());
  const rows = [['Market', 'Yes price', '24h volume']];
  markets.forEach(function (m) {
    rows.push([m.question, Number(JSON.parse(m.outcomePrices)[0]), Math.round(m.volume24hr || 0)]);
  });
  return rows;
}

/**
 * Open Kalshi markets in one series, with Yes bid and ask.
 * In a cell: =KALSHI_SERIES("KXFEDDECISION")
 * @customfunction
 */
function KALSHI_SERIES(series) {
  const url = 'https://external-api.kalshi.com/trade-api/v2/markets?status=open&limit=50&series_ticker=' + encodeURIComponent(series);
  const data = JSON.parse(UrlFetchApp.fetch(url, { muteHttpExceptions: true }).getContentText());
  const rows = [['Market', 'Yes bid', 'Yes ask']];
  data.markets.forEach(function (m) {
    rows.push([m.title + ' ' + (m.yes_sub_title || ''), Number(m.yes_bid_dollars), Number(m.yes_ask_dollars)]);
  });
  return rows;
}

A few Google limits to know. Apps Script allows 20,000 URL fetch calls a day on a consumer account and 100,000 on Google Workspace, and a custom function must finish within 30 seconds. Custom functions recalculate when their inputs change, so for a timed refresh, write a normal function that fills a range and run it from a time-driven trigger.

How do you get prediction market data into Excel?

Excel's Power Query reads JSON from a URL without any code:

1. Go to Data > Get Data > From Other Sources > From Web (or Data > From Web).
2. Paste a URL, for example https://external-api.kalshi.com/trade-api/v2/markets?status=open&limit=50&series_ticker=KXFEDDECISION, and choose Anonymous access.
3. In the Power Query editor, click the List link next to markets, choose To Table, then use the expand button on Column1 to pick the fields you want, such as title, yes_sub_title, yes_bid_dollars and yes_ask_dollars.
4. Change the price columns to Decimal Number, then Close & Load.
5. Refresh with Data > Refresh All, or set a refresh interval in the query's connection properties.

For Polymarket, use a Gamma URL such as https://gamma-api.polymarket.com/markets?active=true&closed=false&order=volume24hr&ascending=false&limit=20. Gamma returns a list at the top level, so choose To Table straight away and expand question, outcomePrices and volume24hr. Note that outcomePrices arrives as text such as ["0.125", "0.875"], so split it to get the Yes price.

How do you get every venue into one sheet?

Each venue needs its own function, its own field names and its own price format, which is where spreadsheets get messy. Predictefy returns markets from 15+ venues with the same columns: title, outcomes with probability prices, 24-hour volume, liquidity and close date. One function or one Power Query then covers every venue. Requests use a bearer key in the Authorization header against https://data.predictefy.com/api/{venue}/fetchMarkets, and the Free plan includes 25,000 credits a month, where one market list costs 1 credit.

Spreadsheet data is a snapshot that can be minutes old. Use it for research and monitoring, and trade from a live order book. Trading involves risk.

Frequently Asked Questions