# Crypto ETF Flows — Zapi reference

> Daily net flows of US spot Bitcoin ETFs per fund (IBIT, FBTC, GBTC, ARKB, BITB, ...) since launch on 2024-01-11, with cumulative flow and current BTC holdings per fund.

**Base URL:** `https://api.zapi.ink`
**Auth:** Send `x-api-key: YOUR_KEY` header on every request. Get a free key at https://zapi.ink/dashboard/keys.
**Response envelope:** success `{ project, data, timestamp }` (`data` is the payload); errors `{ content, message, errors }`
**Rate limit:** free tier 100 req/min and 600 req/month; paid plans at https://zapi.ink/pricing.

**Related:**
- Detail page: https://zapi.ink/api/finance/etf
- Category in the catalog: https://zapi.ink/?cat=finance
- Category reference: https://zapi.ink/category/finance/llms.txt
- Concise index: https://zapi.ink/llms.txt
- Full reference: https://zapi.ink/llms-full.txt

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## Crypto ETF Flows

**Category:** finance · **Slug:** `etf`
**Detail page:** https://zapi.ink/api/finance/etf

Daily net flows of US spot Bitcoin ETFs per fund (IBIT, FBTC, GBTC, ARKB, BITB, ...) since launch on 2024-01-11, with cumulative flow and current BTC holdings per fund.

**Tags:** finance, crypto, bitcoin, etf, flows

### US Spot Bitcoin ETF Flows (Daily)

Daily net flows of every US spot Bitcoin ETF since 2024-01-11 (one row per US trading day): total netFlowUsd, perFund (IBIT, FBTC, BITB, ARKB, BTCO, EZBC, BRRR, HODL, BTCW, MSBT, GBTC, BTC), cumulativeNetFlowUsd, complete flag (false while a fund has not reported yet; missing values are null, never 0) and revisedAt when a past day changes. Includes current BTC holdings per fund and total net assets. Use days (latest N trading days) or startDate/endDate with optional limit/page. Data: Farside Investors + BitcoinTreasuries (bitbo).

- **Method:** `GET`
- **Endpoint:** `https://api.zapi.ink/v1/finance:etf/btc-flows`
- **Cache TTL:** 300s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `startDate` | string | query | no | Optional. First US trading day (YYYY-MM-DD). History starts 2024-01-11 |
| `endDate` | string | query | no | Optional. Last US trading day, inclusive (YYYY-MM-DD). Default: latest reported day |
| `days` | number | query | no | Number of latest trading days when no startDate/endDate is given. Default 30 |
| `limit` | number | query | no | Optional, with startDate/endDate. Rows per page (oldest first). Default: all rows in range |
| `page` | number | query | no | Optional, with startDate/endDate. Page number when `limit` is set. Default 1 |

**cURL:**
```bash
curl "https://api.zapi.ink/v1/finance:etf/btc-flows?startDate=2024-01-11&endDate=2024-12-31&days=30&limit=250&page=1" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zapi.ink/v1/finance:etf/btc-flows?startDate=2024-01-11&endDate=2024-12-31&days=30&limit=250&page=1", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zapi.ink/v1/finance:etf/btc-flows?startDate=2024-01-11&endDate=2024-12-31&days=30&limit=250&page=1",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

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_Generated: 2026-11-06T07:10:56.387Z_