What Is an ETF?

"I own 1,249 companies." Do you, really?

An ETF is one fund you buy on the exchange, like a share.

Behind it sits a basket, held apart from the fund firm by a depositary. When buyers want more, a market maker asks the fund for new shares.

The basket copies an index, so big firms get more of your money.

In a €131 billion world ETF, the top 10 firms hold 27.78%: €28 of every €100 (justETF, 30 Sep 2026).

Did you know how much of your ETF sits in its top 10?

Education, not investment advice.

Read the sheet as text

What Is an ETF?
A fund you buy like a share. Here, €100 in a world ETF, opened up.

On the Exchange: a market maker sells it, and can ask the fund for more.
One Basket: 1,249 firms, kept apart by a depositary.
Weighted by Size: copied from the index: big firms get more.
A Fee Inside: 0.20% a year: 20 cents on €100.

The catch: 10 firms of 1,249 → €28 of every €100: the top 10 hold 27.78% of a €131 billion world ETF (justETF, 30 Sep 2026).
The top 3 alone: Nvidia €5.79, Apple €5.39, Microsoft €3.99.

Sources (3)

iShares Core MSCI World UCITS ETF USD (Acc), IE00B4L5Y983justETF, read 2 Nov 2026: 1,249 holdings, top 10 = 27.78%, Nvidia 5.79%, Apple 5.39%, Microsoft 3.99% (holdings as of 30/09/2026); TER 0.20%; fund size EUR 131,264 m. Named here only. Checked 2026-11-02.
Key Investor Information, same fundBlackRock, accurate as at 9 Feb 2026: in normal circumstances only authorised participants deal directly with the fund, other investors trade on stock exchanges; the depositary is State Street Custodial Services (Ireland) Limited; the index is weighted by free-float market capitalisation. Checked 2026-11-02.
KID, State Street SPDR MSCI World UCITS ETF19 Feb 2026: the fund generally issues and redeems shares only with certain institutional investors; market prices may be above or below the daily NAV. Checked 2026-11-02.