Predexy tracks the same prediction market question across multiple platforms simultaneously. Because “Will BTC reach $100k by 2026?” might trade on Polymarket at 0.62, on Limitless at 0.58, and on Predict.fun at 0.65, you need a single reference point to understand where the market actually stands — and how much the platforms disagree. That reference point is the index.
Canonical questions
Every market Predexy tracks is linked to a canonical question — a single logical event that may be listed under different titles across multiple platforms. When you browse Predexy, you are always looking at canonical questions, not raw platform markets. The market_count and platform_slugs fields on each item tell you how many platforms are currently listing that question and which ones.
Index price
The index_price is a volume-weighted consensus probability on a 0–1 scale, where 0 means the outcome is considered impossible and 1 means it is considered certain. Platforms with higher 24-hour trading volume contribute more weight to the index, so a high-volume venue like Polymarket carries more influence than a low-volume one.
The index price is not a simple average. Volume-weighting means that thin,
illiquid markets have less influence on the consensus than deep, actively
traded ones.
Divergence
Divergence measures how far apart the platforms are from each other. Technically, it is the weighted standard deviation of Yes prices across platforms. A low divergence means the platforms broadly agree; a high divergence means there is significant disagreement — and potentially an opportunity worth investigating.
Predexy groups divergence into three categories:
| Category | Divergence value | What it means |
|---|
low | < 2% | Platforms are in close agreement |
medium | 2–5% | Meaningful spread worth monitoring |
high | > 5% | Significant disagreement across platforms |
The DiscoverItem schema
Every item returned by the discovery endpoint includes these fields:
{
"id": "3f2d1c4a-...",
"title": "Will BTC reach $100k by 2026?",
"index_price": 0.62,
"divergence": 0.034,
"divergence_category": "medium",
"best_buy_price": 0.58,
"best_buy_platform": "limitless",
"spread_bps": 400,
"market_count": 3,
"platform_slugs": ["polymarket", "limitless", "predictfun"]
}
| Field | Type | Description |
|---|
id | UUID | Canonical question identifier |
title | string | Canonical question title |
index_price | number (0–1) | Volume-weighted consensus probability |
divergence | number | Weighted standard deviation of prices across platforms |
divergence_category | low | medium | high | Bucketed divergence level |
best_buy_price | number (0–1) | Cheapest Yes price available across all platforms |
best_buy_platform | string | Slug of the platform offering the cheapest price |
spread_bps | integer | Gap between cheapest and most expensive price, in basis points |
market_count | integer | Number of platforms listing this question |
platform_slugs | string[] | Slugs of all platforms listing this question |
The IndexResult schema
When you fetch a specific question via GET /api/v1/questions/{id}, the response includes a detailed index object:
{
"index_price": 0.62,
"divergence": 0.034,
"divergence_category": "medium",
"platform_count": 3,
"best_buy_price": 0.58,
"best_buy_platform": "limitless",
"best_sell_price": 0.65,
"best_sell_platform": "predictfun",
"spread_bps": 700,
"platform_prices": {
"polymarket": 0.62,
"limitless": 0.58,
"predictfun": 0.65
}
}
platform_prices map gives you the individual Yes price for each platform, so you can see at a glance exactly where the disagreement lies and which venues are on either end of the spread. 
