---
title: "ETF (exchange-traded fund)"
description: "An ETF is an open-ended fund whose shares trade on a stock exchange during the day, with creations and redemptions by authorised participants keeping the price close to NAV."
canonical: https://fundfactsapi.com/glossary/etf
published: 2026-09-04
updated: 2026-09-04
publisher: FundFacts API
---

# ETF (exchange-traded fund) (ETF, Exchange-traded fund, UCITS ETF, Tracker)

> An ETF is an open-ended fund whose shares trade on a stock exchange during the day, with creations and redemptions by authorised participants keeping the price close to NAV.

## Definition

An **exchange-traded fund (ETF)** is an investment fund whose shares are listed on one or more stock exchanges and can be bought and sold throughout the trading day like a share. Large institutions called authorised participants create and redeem ETF shares in bulk directly with the fund, which keeps the market price close to the fund's [NAV](https://fundfactsapi.com/glossary/nav). Most ETFs track an index, though actively managed ETFs exist. In Europe, ETFs are almost always [UCITS](https://fundfactsapi.com/glossary/ucits) funds and must carry "UCITS ETF" in their name.

## Why it matters

ETFs have made low-cost, transparent index exposure available to everyone, and they publish their full holdings daily, which makes them well suited to [look-through](https://fundfactsapi.com/glossary/look-through) analysis. Because a single share class is listed on several exchanges, it has one ISIN but several tickers and trading currencies, which is why fund data should always be keyed by ISIN.

## In the API

`securityType` distinguishes ETFs from traditional funds, `structure` gives the legal wrapper, and holdings data is available in `keyFacts.holdings` and `topHoldings`. Example values:

```json
{
  "securityType": "ETF",
  "structure": "UCITS (Irish ICAV)",
  "keyFacts": { "holdings": 1350 },
  "topHoldings": [{ "name": "Example Inc", "weight": 4.8, "isin": "US0000000000" }]
}
```

The example ISIN inside `topHoldings` is a placeholder.

## Common pitfalls

Exchange-traded commodities (ETCs) and exchange-traded notes (ETNs) trade like ETFs but are debt instruments, not funds, and do not carry UCITS protections. An ETF's market price can deviate from NAV, especially when the underlying market is closed. Physical and synthetic ETFs deliver the same index return by different means; see [replication method](https://fundfactsapi.com/glossary/replication-method).

## In the FundFacts API payload

- `securityType`
- `structure`
- `keyFacts.holdings`
- `topHoldings`

## About FundFacts API

FundFacts turns any fund or ETF ISIN into one dated factsheet (fees and KID costs, the 1–7 risk indicator, holdings, sector and country exposure, returns) read from the fund house's own documents: as a client-ready PDF under your firm's name for advisers and wealth managers, as JSON through its API for developers, or inside ChatGPT and Claude through its MCP server.

FundFacts works inside ChatGPT and Claude as a connector (a remote MCP server): ask about any fund or ETF by ISIN, ticker or name and the assistant answers from FundFacts' dated figures, fees, risk, holdings, exposure and returns, with fund cards, side-by-side comparisons, holdings overlap and portfolio look-through.

- Free API key, no card: https://fundfactsapi.com/signup
- Documentation: https://fundfactsapi.com/docs (OpenAPI: https://fundfactsapi.com/openapi.json)
- MCP server: https://fundfactsapi.com/api/mcp (set-up for every client: https://fundfactsapi.com/mcp-server)
- Pricing: https://fundfactsapi.com/pricing
- Site index for AI assistants: https://fundfactsapi.com/llms.txt
- Informational data, not investment advice.