# ETF Holdings – Spot Bitcoin & Ethereum ETF Data

> ETF Holdings – Spot Bitcoin & Ethereum ETF Data is a paid API for AI agents from api.agentstools.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns latest per-fund holdings (coin units, market value, shares outstanding) and aggregate AUM stats for spot Bitcoin or Ethereum ETFs from issuer disclosures, for US or HK markets.

## Facts

- Endpoint: GET https://api.agentstools.dev/etf/holdings
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/etf-holdings-spot-bitcoin-ethereum-etf-data-dab8647a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vhJu_DxazCW-rDCzfAFpU

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 etf-holdings-spot-bitcoin-ethereum-etf-data-dab8647a
```

Example prompt: Can you pull the latest holdings data for all US spot Bitcoin ETFs — I want to see how many BTC units each fund holds, their market values, and what fraction of total AUM the biggest fund controls?

## When to prefer this

Use this endpoint when you need a single normalized call that aggregates spot crypto ETF holdings across all major issuers for a given asset and region, rather than scraping individual fund disclosures. Ideal for agents that need AUM concentration metrics, per-fund coin unit counts, and market values in one structured response without building custom ETF data pipelines.

## Known failure modes

- Invalid asset enum value (not 'btc' or 'eth') returns a 422 validation error
- Invalid region enum value (not 'us' or 'hk') returns a 422 validation error
- HK region is currently a scaffold and may return incomplete or placeholder data
- Issuer disclosure data may lag real-time prices, causing stale market values
- Payment failure (insufficient USDC balance) returns a 402 error

## How this service works

Latest holdings for spot Bitcoin or Ethereum ETFs from issuer disclosures: per-fund coin units (or shares), market value and shares outstanding, plus total AUM across funds and the largest fund's AUM share. One normalized call.

## Output

Returns a normalized JSON object with per-fund data (coin units or shares held, market value, shares outstanding) sourced from issuer disclosures, plus aggregate metrics: total AUM across all funds in the requested asset/region, and the AUM share held by the largest single fund.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "asset",
      "region"
     ],
     "properties": {
      "asset": {
       "enum": [
        "btc",
        "eth"
       ],
       "type": "string",
       "description": "Crypto asset whose spot ETFs to report: btc or eth."
      },
      "region": {
       "enum": [
        "us",
        "hk"
       ],
       "type": "string",
       "description": "ETF listing region: us (live) or hk (scaffold)."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/etf-holdings-spot-bitcoin-ethereum-etf-data-dab8647a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.agentstools.dev](https://www.zero.xyz/host/api.agentstools.dev/llms.txt)