The VanEck Morningstar Wide Moat ETF (ASX: MOAT) is one of the more popular exchange-traded funds (ETFs) on the ASX, and certainly one of the most popular ETFs not of the broad index fund variety.

How do we know? Well, because this fund currently has almost $1 billion in assets under management.

As such, we can conclude that quite a few ASX investors have MOAT units in their investment portfolios.

However, given that the VanEck Wide Moat ETF is not a simple index fund, it can be hard to pin down exactly what it is investors are buying when they are purchasing MOAT units.

Today, let's examine that question a little more thoroughly by analysing the shares that currently make up this ASX ETF's underlying portfolio.

What's in a MOAT for this ASX ETF?

As its name suggests, the VanEck Wide Moat ETF invests in a basket of stocks that have all been identified as possessing a wide 'economic moat'. This term, originally coined by legendary investor Warren Buffett, refers to an intrinsic competitive advantage that a company might possess.

This could come in the form of a strong brand that commands loyalty from customers, a low-cost advantage in producing goods or services, or selling a product that customers find difficult to substitute.

Buffett himself often tells us that his best investments usually display some of these characteristics. We can certainly see this in action if we examine some of Berkshire Hathaway Inc's famous investments. To illustrate, no one can deny the brand power of Apple, Coca-Cola, or American Express.

But what about the ASX's VanEck Wide Moat ETF?

Well, VanEck's most recent data tells us that some of MOAT's current holdings include Boeing, Walt Disney, Alphabet, Campbell's Company, Nike, and Altria.

Already, we can see how these companies can be identified as possessing some kind of moat.

Boeing is one of the world's largest defence companies and forms one half of a virtual duopoly in aeroplane manufacturing. Entertainment giant Disney, Marlboro-maker Altria, and athletics pioneer Nike all possess formidable intellectual property and powerful brands. Alphabet's Google forms a virtual monopoly of its own with search. While Campbell's Company is the lowest-cost manufacturer of soups and stocks (the cooking kind) in its markets.

Investing in these kinds of companies has worked well for the VanEck Wide Moat ETF for a while now. As of 31 May, MOAT units have returned an impressive 14.59% per annum since the ETF's founding in 2015. Let's see what kind of numbers the ETF can throw up going forward.