Polymarket Arbitrage Finder — Groups Priced Under $1

What it does: Finds Polymarket events that are a group of Yes/No markets that can't all happen, and prices the whole group: buy every outcome, or sell every outcome.

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

You get: One row per group: cost to buy one share of every outcome, money back from selling one of each, profit % for buy-all and sell-all, whether every outcome takes orders, liquidity, price change. 15 events per topic by default; overlapping groups get no profit %.

Price: $0.02 per topic. +$0.002 per market if you also want each market (off by default). A topic with no priceable group is never charged.

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

What you get

For each topic you enter, the tool takes up to 15 Polymarket events (you can raise this to 50) and prices each one as a group — buying one share of every outcome, or selling one of each.

One summary row per topic, with how many events were found, how many groups could be priced, how many had a positive return, the spread of those returns, and the best one found.

One row per priced group:

field	meaning
eventTitle / url / endDate	the event, its link, and when it closes
marketCount / marketsDropped	how many outcomes were priced, and how many were left out because they are closed or paused
sumBestAsk	cost of buying one share of every outcome
buyAllEdgePct	(1 - sumBestAsk) x 100 — locked-in return if positive
sumBestBid	proceeds from selling one share of every outcome
sellAllEdgePct	(sumBestBid - 1) x 100
exhaustive / tradable	whether the outcomes really are one full group, and whether every one of them currently accepts orders
edgeUnavailableReason	plain-English reason when no return figure is given
spreadStats	how wide the gap between bid and ask is across the group — lowest, middle 50% range, highest
liquidityUsd / volume24hrUsd	money resting in the order books, and 24h traded volume
momentum1wPct / momentum1mPct	typical outcome price change over a week and a month

Groups smaller than 3 outcomes are skipped by default (a plain Yes/No pair always adds up to $1, so it can never show a gap). Turning on "include individual markets" also returns every market inside the reported groups, one row each.

The trap this Actor refuses to fall into

A return is only real when exactly one of the outcomes can happen and one of them must — Polymarket marks such a group negRisk (its own term for it). Sets of related-but-overlapping questions ("Fed rate cut by March?", "...by June?") add up to far below $1 and look like a 75% profit. They are not.

Overlapping sets are returned with exhaustive: false and no return figure at all, plus a one-line reason. Nothing in the output invites you to trade a number that does not exist. The same applies when some outcomes of an event are closed or paused: what is left is not the whole group, so it gets no figure either.

What one row looks like

Measured on 2026-08-09 (real run) — the summary row for the topic fed rate, a few fields left out for length

{
  "type": "arbitrage_summary",
  "topic": "fed rate",
  "eventsFound": 26,
  "basketsEvaluated": 4,
  "basketsPriced": 3,
  "basketsNotExhaustive": 1,
  "positiveEdgeBaskets": 1,
  "tradablePositiveEdgeBaskets": 1,
  "bestBuyAllEdge": {
    "eventTitle": "How many Fed rate hikes in 2026?",
    "buyAllEdgePct": 2.1,
    "sumBestAsk": 0.979,
    "marketCount": 6,
    "tradable": true,
    "url": "https://polymarket.com/event/how-many-fed-rate-hikes-in-2026-20260623190717369"
  },
  "totalLiquidityUsd": 4181449.23,
  "checkedAt": "2026-08-09T18:43:26.878092+00:00"
}

Price

$0.02 per topic scanned — each topic you enter is charged separately, so three topics in one run cost $0.06. Individual markets are $0.002 each and off by default. A topic where nothing could be priced is never charged. You pay per topic; there is no monthly fee.

Input

{
  "topics": ["fed rate", "election"],
  "minMarketsPerBasket": 3,
  "minEdgePct": 0
}

minEdgePct decides what is returned, not what is counted: the summary row still counts every group that was priced. Set it to 0 to see them all.

Reads Polymarket's public data only, no login, requests spaced out. Nothing is kept between runs — every run re-reads the live prices.

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.
• A topic with nothing priceable = no charge. A topic that does get a price costs $0.02 even when the profit comes out negative — that number is the result you asked for.
• 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 Odds, Volume & Top Markets by Topic
• Polymarket Markets — Odds, Bid/Ask, Volume, One Row Each
• 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.