Prediction Market Movers: Kalshi & Polymarket Odds Alerts

Find out what the world just changed its mind about. This Actor scans Kalshi and Polymarket and returns only the markets whose odds moved since your last run, along with newly opened markets and markets that resolved. Each result comes with a ready-to-send headline like:

US-Iran ceasefire continues through November 30? 62% → 41% (−21.0 pts since last run)

Schedule it every hour and connect it to Slack, email, a spreadsheet or your own app, and you have a live alert feed for elections, geopolitics, the Fed, crypto, or anything else traded on prediction markets.

Why use it

• Signals, not data dumps. Other tools hand you thousands of markets. This one remembers the odds from your previous run and returns only the markets that changed, so you can act on the move rather than search for it.
• Kalshi and Polymarket in one format. Odds are always the "Yes" probability in percent, and changes are always in percentage points, whichever platform the market is on.
• New and resolved markets. It catches markets that just opened, and reports the outcome of markets that settled since the last run, along with what the odds were before.
• Noise filters built in. Thinly traded markets and markets about to close (which swing to 0% or 100% as they settle) are skipped by default.
• Official public APIs. It reads the platforms' public market data endpoints, with no login or browser. A full scan of both platforms takes about 20 seconds.

Use cases

• Newsrooms and analysts: get alerted when the market's view of an election, a ceasefire or a rate decision shifts sharply.
• Traders: watch odds moves across both platforms from one feed.
• Research and dashboards: build a time series of odds by running the Actor on a schedule.
• AI agents: give your agent a compact, current picture of what markets expect to happen.

Input

Field	What it does
Search terms	Only include markets whose title, outcome or tags contain one of these words (iran, election, fed, bitcoin). Empty means all markets.
Categories	Only include markets in these categories or tags (Politics, Elections, Economics, Crypto).
Exclude terms	Skip markets containing any of these words.
Mode	movers returns movers, new and resolved markets. snapshot returns every matching market.
Measure moves over	sinceLastRun (default), 1h, 24h or 7d. The 1h and 7d windows are Polymarket only.
Minimum change	Percentage points needed to count as a mover (default 5).
Include new / resolved markets	Both on by default.
Minimum 24h volume	Skip thinly traded markets (default $1,000).
Skip markets closing within	Hours (default 24). Set to 0 to include them.
Platforms	Polymarket, Kalshi, or both.

How "since last run" works

The Actor saves the odds of every matching market after each run, separately for each combination of platforms and filters. The next run with the same filters compares against them. The first run has no history yet, so it reports 24-hour movers instead. Schedule the Actor hourly or daily to get a continuous feed.

Example input

{
  "searchTerms": ["iran", "ceasefire", "hormuz"],
  "mode": "movers",
  "moverWindow": "sinceLastRun",
  "minChangePoints": 5
}

Output

{
  "signal": "moved",
  "headline": "US-Iran ceasefire continues through...? — November 30: 62% → 41% (−21.0 pts since last run)",
  "platform": "polymarket",
  "eventTitle": "US-Iran ceasefire continues through...?",
  "question": "US-Iran ceasefire continues through November 30?",
  "outcomeLabel": "November 30",
  "probabilityPct": 41,
  "previousProbabilityPct": 62,
  "changeSinceLastRun": -21,
  "change1h": -3.5,
  "change24h": -20.5,
  "change7d": 4,
  "yesBidPct": 40.5,
  "yesAskPct": 41.5,
  "volume24h": 250000,
  "volume": 37930696,
  "closesAt": "2026-11-30T00:00:00Z",
  "status": "open",
  "result": null,
  "category": "Politics",
  "tags": ["Politics", "Iran"],
  "url": "https://polymarket.com/event/us-iran-ceasefire-continues-through",
  "previousRunAt": "2026-11-03T06:00:00.000Z",
  "scrapedAt": "2026-11-03T12:00:00.000Z"
}

signal is one of moved, new, resolved or snapshot. Resolved markets include result (e.g. YES, NO, or the winning outcome name). Results are sorted with resolved first, then the biggest moves.

A SUMMARY record in the run's key-value store shows how many markets were scanned on each platform, the counts of each signal, and the window used.

Pricing

You pay per result returned. Scanning is free, so a run where nothing moved costs almost nothing. Set a maximum cost per run in the run options and the Actor stops cleanly when it's reached.

FAQ

Why did my first run return so many results? With no earlier run to compare against, the first run reports 24-hour moves. From the second run on, you'll only see what changed since the previous run.

Can I track two different topics? Yes. Each combination of search terms, categories and platforms keeps its own history, so an "iran" task and a "fed" task won't interfere with each other.

Is this financial advice? No. This is market data, shown as it appears on each platform.