# Polymarket Whale Holders Lookup

> Polymarket Whale Holders Lookup is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-28).

Returns the largest token holders for each outcome of a Polymarket prediction market, identified by wallet address and share count, plus a sum of the top holders' stakes.

## Facts

- Endpoint: POST https://api.vextorium.com/v1/polymarket-holders?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polymarket-whale-holders-lookup-43fa3131
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aGgijDEk2lguwh8_JVX9t

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability polymarket-whale-holders-lookup-43fa3131 -d '<json body>'
```

Example prompt: Can you show me the top whale holders for each outcome of the Polymarket market with slug 'will-oprah-winfrey-win-the-2028-democratic-presidential-nomination'? Give me the top 5 holders.

## When to prefer this

Use this endpoint when you need granular, wallet-level intelligence on who the largest bettors are in a specific Polymarket prediction market. It is ideal for smart-money analysis, whale tracking, and sentiment gauging via position concentration. Prefer this over generic Polymarket APIs when you specifically need top-N holder rankings per outcome with stake sums rather than aggregate market volume or price data.

## Known failure modes

- Invalid or non-existent slug returns an error or empty results
- Limit value outside 1-20 range may cause a validation error
- Polymarket market not yet resolved or very new may have sparse holder data
- Rate limiting or payment failure (x402) if USDC balance is insufficient
- Network timeout if Polymarket's public API is slow or unavailable

## How this service works

558 pay-per-call data APIs for AI agents: Solana and EVM on-chain data, tokenized stocks, DeFi, Hyperliquid, economy and official statistics, FX, validation, web and developer tools. Pay in USDC via x402.

## Output

A JSON object containing the market slug, the question text, the data source (Polymarket public API), and an array of outcome results. Each outcome includes its label (e.g. 'Yes'/'No'), an ordered list of the largest holders with their wallet address and share count, and the combined stakes sum of all top holders for that outcome.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "slug": {
   "type": "string"
  },
  "limit": {
   "type": "integer",
   "description": "1-20"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "slug": "will-oprah-winfrey-win-the-2028-democratic-presidential-nomination",
  "source": "Polymarket (public data API)",
  "results": [
   {
    "result": "Yes",
    "largest": [
     {
      "stakes": 2441726.05,
      "wallet": "0x5d189e816b4149be00977c1a3c8840374aec4972"
     },
     {
      "stakes": 81912.91,
      "wallet": "0xbefa95c276ee8ef6ff3ef43d1c1c454f52bc300d"
     }
    ],
    "stakes_sum": 2603019.75
   },
   {
    "result": "No",
    "largest": [
     {
      "stakes": 3132849.11,
      "wallet": "0xa5ef39c3d3e10d0b270233af41cac69796b12966"
     },
     {
      "stakes": 231.63,
      "wallet": "0xd7508a67410adb7bb0004f5073dc285a750b5235"
     }
    ],
    "stakes_sum": 3133258.36
   }
  ],
  "question": "Will Oprah Winfrey win the 2028 Democratic presidential nomination?"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polymarket-whale-holders-lookup-43fa3131/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)