Polymarket Odds, Volume & Top Markets by Topic

What it does: Searches Polymarket for a topic and returns one summary of the odds, volume and liquidity across its markets, plus the top markets.

You enter: One or more topics, e.g. bitcoin or fed rate cut.

You get: One row per topic: events found, total volume and liquidity (USD), typical volume per market, leading-outcome odds (median and range), median days until markets settle, top 5 markets with links — measured on the topic's 25 biggest markets by volume.

Price: $0.02 per topic that returns markets. +$0.002 per market if you also want each one listed (off by default). A topic that matches nothing is not charged.

Example: enter bitcoin → 50 events found · measured on its 25 biggest markets by volume · total volume $56,478,441 · median volume per market $1,586,292 · leading outcome median 97% · median 136 days until they settle (real run, 2026-08-17)

Unofficial — not affiliated with Polymarket. Reads public pages only.

Why market stats?

Polymarket is the world's largest prediction market: real people betting real money on elections, crypto, sports, AI milestones, and world events. Its odds are widely cited as a live probability signal — but its own API returns hundreds of markets per topic, in inconsistent formats. This Actor turns one topic keyword into one summary row:

• Track a narrative — total volume and liquidity behind a topic, in one number
• Get the odds snapshot — leading-outcome probabilities across the markets it measured (the topic's 25 biggest by volume, or as many as you ask for)
• Feed your AI agent, model, or dashboard — clean JSON, USD-native
• Monitor resolution timing — median days until those markets settle

Price

You pay per topic; there is no monthly fee.

What you pay for	Price
Market summary (one per topic)	$0.02
One row per market (optional, off by default)	$0.002 each

• A default run costs a flat $0.02 per topic — the summary is the product. 10 topics = $0.20.
• Want every matched market too? Turn on Include individual markets: e.g. 25 markets add $0.05.
• Topics with no matched markets are never charged.

Input example

{
    "topics": ["bitcoin", "fed rate cut"],
    "activeOnly": true,
    "maxMarketsPerTopic": 25
}

Output

One market_summary row per topic.

Measured on 2026-08-17 (real run, topic bitcoin; topMarketsByVolume returns 5 markets — the 2 biggest are shown, the rest as ...)

{
    "type": "market_summary",
    "topic": "bitcoin",
    "eventsFound": 50,
    "sampledMarkets": 25,
    "totalVolumeUsd": 56478441,
    "totalLiquidityUsd": 2575491,
    "volumeStatsUsd": { "min": 794305.9442499998, "p25": 1128331, "median": 1586292, "p75": 2748867, "max": 5390599.958966998, "average": 2259138 },
    "liquidityStatsUsd": { "min": 55071.84925, "p25": 80238, "median": 100160, "p75": 118522, "max": 196811.78055, "average": 103020 },
    "leadingOutcomePctStats": { "min": 56, "p25": 92, "median": 97, "p75": 98, "max": 99, "average": 92 },
    "medianDaysToResolution": 136,
    "topMarketsByVolume": [
        {
            "question": "Will Bitcoin reach $250,000 by December 31, 2026?",
            "leadingOutcomePct": 98.4,
            "volumeUsd": 5390599.958966998,
            "endDate": "2027-01-01T05:00:00Z",
            "url": "https://polymarket.com/market/will-bitcoin-reach-250000-by-december-31-2026-579-442"
        },
        {
            "question": "Will Bitcoin dip to $55,000 by December 31, 2026?",
            "leadingOutcomePct": 55.5,
            "volumeUsd": 5071401.550396003,
            "endDate": "2027-01-01T05:00:00Z",
            "url": "https://polymarket.com/market/will-bitcoin-dip-to-55000-by-december-31-2026-527-627-868-745-188-361-314-673-612-946-821-624-855-557-684-381-884-939-182-939-516"
        },
        "..."
    ],
    "checkedAt": "2026-08-17T17:45:32.411037+00:00"
}

Plus (optional) one row per measured market, with question, outcomes, probabilities, best bid/ask, volume, liquidity, end date and a direct polymarket.com URL.

Use with AI agents

Works out of the box with the Apify MCP server, so Claude, ChatGPT, and other MCP-enabled agents can check live prediction-market sentiment autonomously — for example inside a research, trading-signal, or news-monitoring workflow.

Fair use & data

• Uses only Polymarket's official public API (Gamma) — no login, no personal data
• Read-only, one search request per topic, 1 second between topics
• Not affiliated with Polymarket. Odds are market prices, not guaranteed probabilities; do your own research

Roadmap

Kalshi comparison, historical odds tracking, and topic-level alerting. Feedback via issues is very welcome — tell me what your workflow needs.

If something goes wrong

• Wrong number or a failed run? Open a ticket on the Issues tab. I read every one and reply within 2 business days (Japan time).
• You never get a fake "empty" result. If the site can't be read, the run fails and says so.
• No results = no charge. You only pay for results you actually get.
• Checked every week. An automatic test runs this tool weekly; if the site changes, I fix it.
• Public pages only. No login, no personal data, and it goes easy on the site.

More tools by the same author

• Polymarket Markets — Odds, Bid/Ask, Volume, One Row Each
• Polymarket Arbitrage Finder — Groups Priced Under $1
• Kalshi Arbitrage Finder — Groups Priced Against $1
• Polymarket vs Kalshi Arbitrage — Same Question, Two Prices

All tools (Japan marketplaces, real estate, jobs, racing, prediction markets): https://apify.com/jpmarketdata

Disclaimer

Unofficial, independent tool — not affiliated with, endorsed by, or sponsored by Polymarket. Product names and logos belong to their owners and only say where the data comes from. Data is read from public pages, for market research; check before you act on it.