Public goods infrastructure for prediction markets. One endpoint returns a canonical ticker, a manipulation-resistant price, and cross-platform context for any market that serves the public interest.
Volume-weighted pricing across Polymarket and Kalshi. Reportability scoring built in. No aggregation required.
{
"ticker": "BWR-DEM-WIN-PRES-2028",
"title": "Will the Democratic nominee win the 2028 presidential election?",
"category": "ELECTORAL",
"bellwether_price": 0.42,
"price_label": "6h VWAP across platforms",
"price_tier": 1,
"robustness": {
"cost_to_move_5c": 47200,
"reportability": "reportable"
},
"platforms": ["polymarket", "kalshi"],
"volume_usd": 2840000
}
Markets across platforms can't be compared, most prices are trivially manipulable, and there's no standard way to identify what event a market is actually about.
The same question appears on Polymarket and Kalshi with different wording, different resolution criteria, and no shared identifier. If two markets resolve under different conditions, their probabilities are fundamentally different — and comparing them is meaningless.
98.7% of prediction markets lack the liquidity to resist manipulation. Most can be moved 5¢ for less than $1,000. A price that can be bought isn't a consensus — it's a vulnerability.
A market's price is just its last trade. That could be informed money, a fat finger, or someone trying to move a number before a screenshot goes viral. Without volume-weighting over time, you're citing an anecdote, not a signal.
One endpoint. Every prediction market that serves the public interest.
Every market includes the dollar cost to move its price by 5¢. Instantly know whether a prediction reflects deep conviction or thin liquidity.
Our matching engine maps identical events across Polymarket and Kalshi into a single canonical ID. Same event, one price.
6-hour VWAP with automatic fallbacks to 12h and 24h windows smooths out noise and manipulation attempts. The price that reflects sustained belief, not the last trade.
Every market classified as Reportable, Caution, or Fragile based on how much capital it takes to move the price. Know instantly whether a market reflects genuine consensus or can be bought for a few thousand dollars.
Live prices updated continuously with 30-second cache. Current order book depth, VWAP, and reportability scores for every tracked market.
Four steps between a market ticker and a manipulation-resistant probability you can cite with confidence.
Search by ticker, category, or keyword. Every prediction market across Polymarket and Kalshi is indexed.
Cross-platform prices merged into a single canonical record. Matched markets identified automatically by our engine.
Every market scored for manipulation resistance. Cost-to-move-5¢ tells you whether the price reflects real consensus or thin liquidity.
Volume-weighted prices, reportability tiers, and order book depth give you everything you need to use market data responsibly.
The Tape API is live. If you're a newsroom, researcher, or builder working with prediction market data, we'd like to hear from you.