Prediction Markets Scraper - Polymarket, Kalshi & Manifold

Scrape live prediction markets across the three biggest platforms - Polymarket, Kalshi, and Manifold - in one run, one unified schema. Get markets, implied probabilities, prices, volume, and liquidity for politics, sports, crypto, economics, and more.

Most prediction-market scrapers cover a single platform and hand back that platform's raw shape. This Actor reads all three official public APIs and normalizes everything into one consistent schema - implied probability, favorite outcome, volume, liquidity, and resolution dates - ready for trading research, dashboards, journalism, bots, or "information finance" content.

✅ What you get / ❌ what this isn't

This Actor gives you	This Actor is not
Live markets from Polymarket, Kalshi, and Manifold in one unified schema	Not trading or betting advice
Implied probability, outcome prices, favorite outcome per market	Not a way to place trades or move funds
Volume and liquidity, with an explicit unit per platform	Not affiliated with Polymarket, Kalshi, or Manifold
Per-platform roll-up: market count, total volume, top markets	Not a full historical tick/orderbook archive
Reliable official-API reads (no anti-bot, no proxy needed)	Not a guarantee a specific market exists at run time

🔎 Why use this Actor

• Compare odds for the same event across multiple prediction markets.
• Track politics, sports, crypto, and economic markets in one dataset.
• Power a dashboard, newsletter, or bot with live implied probabilities.
• Research market sentiment and volume on a topic with a keyword filter.
• Feed normalized market rows into spreadsheets, a warehouse, or an LLM pipeline.

🗂️ What data you get

Field	Type	Description
platform	string	polymarket, kalshi, or manifold
question	string	The market question
category	string	Market category when the platform exposes one
outcomes	array	Outcome labels
outcomePrices	array	Price per outcome, 0-1 (implied probability)
yesProbability	number	Implied probability of the Yes/primary outcome (binary markets)
favoriteOutcome, favoriteProbability	string, number	Highest-priced outcome and its probability
volume, volumeUnit	number, string	Traded volume and its unit (USD / contracts / mana)
liquidity, openInterest	number	Platform-native liquidity; open interest (Kalshi)
status	string	open, closed, resolved, etc.
startDate, endDate	string	Market open and close/resolution dates
url	string	Link to the market

Plus a per-platform summary row: market count, total volume, markets with a price, and the top markets by volume.

👥 Who it's for

• Traders and quant hobbyists comparing odds across venues.
• Journalists and researchers covering prediction markets.
• Dashboard, newsletter, and bot builders.
• Sports, politics, and crypto analysts tracking sentiment.
• Data teams building normalized prediction-market datasets.

Example tasks

• Scrape Polymarket election odds
• Track crypto prediction markets
• Compare odds across Polymarket, Kalshi and Manifold

⚙️ How to scrape prediction markets

1. Open the Actor on Apify.
2. Choose which platforms to scrape (all three by default).
3. Optionally add a keyword (for example election, bitcoin, fed) and pick open, closed, or all markets.
4. Choose how many markets to collect per platform.
5. Run the Actor.
6. Open the dataset view for Markets or Platform summaries.
7. Export JSON, CSV, Excel, HTML, RSS, or XML, or call the Actor through the Apify API.

📥 Input

{
  "platforms": ["polymarket", "kalshi", "manifold"],
  "status": "open",
  "keyword": "election",
  "maxMarketsPerPlatform": 200
}

📤 Output

{
  "recordType": "market",
  "platform": "polymarket",
  "question": "Will JD Vance win the 2028 US Presidential Election?",
  "outcomes": ["Yes", "No"],
  "outcomePrices": [0.1925, 0.8075],
  "yesProbability": 0.1925,
  "favoriteOutcome": "No",
  "favoriteProbability": 0.8075,
  "volume": 14374508.43,
  "volumeUnit": "USD",
  "liquidity": 510789.8,
  "status": "open",
  "endDate": "2028-11-07T00:00:00Z",
  "url": "https://polymarket.com/event/will-jd-vance-win-the-2028-us-presidential-election"
}

💵 How much does it cost?

The launch price is about $2.00 / 1,000 markets, tier-discounted for higher Apify plans. One market is one charged result; per-platform summary rows are part of the same output.

🔁 Run it on the Apify platform

Schedule recurring odds refreshes, call it from the Apify API, export to CSV/JSON/Excel, or connect the dataset to Make, Zapier, webhooks, a warehouse, or an LLM pipeline.

⚠️ Limits and caveats

• This Actor reads the public APIs of Polymarket, Kalshi, and Manifold. It is not affiliated with them and provides no trading advice.
• Volume units differ by platform and are not directly comparable: Polymarket is USD, Kalshi is contract count, Manifold is mana (play-money). The volumeUnit field on every row makes the unit explicit.
• Manifold multiple-choice markets do not have a single Yes probability, so yesProbability is null for them; binary markets are fully priced.
• Kalshi data is read from its events feed (real, categorized markets) rather than the raw markets feed, which is dominated by auto-generated low-volume combinations.
• Markets are a live snapshot at run time; this Actor is not a full historical orderbook archive.

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❓ FAQ

Which markets does it return by default?

Open markets across all three platforms, ordered by popularity/volume where the platform supports it. Use the keyword filter to narrow to a topic.

How is implied probability calculated?

For binary markets, the outcome price (0-1) is the implied probability. Kalshi uses the last traded price (or the mid of the yes bid/ask when there is no last trade). Polymarket and Manifold expose the probability directly.

Can I compare the same event across platforms?

Yes - run all three platforms with a shared keyword (for example a candidate or team name) and compare yesProbability per platform. A built-in cross-platform match key is on the roadmap.

Does it need a proxy?

No. These are public official APIs that work without a proxy. Enable Apify Proxy only on very large runs if you hit IP rate limits.

🛠️ Support

For bugs or missing fields, open an Actor issue with the run URL, the platform, and the field or behavior you expected.