How ETFs Actually Work
The Basics You Really Need to Know
You’ve probably heard of ETFs. Maybe you’ve even bought one—something that “tracks the S&P 500.”
But what are you actually buying?
How does it work?
And how do you know which type is right for you—especially if you're in the UK or Europe?
This post breaks it down in plain language: how ETFs really work, what to watch out for, and how to choose one that fits your goals.
You Can’t Invest in an Index—But You Can Track It
An ETF—short for Exchange-Traded Fund—is a basket of investments (usually stocks or bonds) that you can buy or sell on a stock exchange, just like a regular share. Most ETFs are designed to track an index, like the S&P 500, FTSE 100, or MSCI World.
But you can’t invest directly in an index. You need a product that mimics it. That’s what an ETF does: it’s a way to get as close as possible to the performance of a market you can’t actually buy.
Distributing vs. Accumulating: What Happens to Dividends?
If the ETF holds dividend-paying stocks, it receives dividends. The question is: what happens next?
Distributing ETFs pay those dividends out to you—usually every quarter.
Accumulating ETFs reinvest the dividends inside the fund automatically.
An accumulating ETF behaves like a total return index: dividends are reinvested automatically, so your returns reflect both price growth and income—not just the movement in share prices.
(If you recall, in my earlier posts on compounding and market timing, I used the concept of total return vs. price return to show the power of reinvested dividends.)
With a distributing ETF, you get cash in your account. You can spend it, reinvest it, or save it. That’s helpful for people who want regular income.
But with an accumulating ETF, you benefit from compounding automatically—without having to take any action. And if you do want income at some point, you can always sell a small number of shares. Just bear in mind: doing this may involve transaction costs—typically a few basis points, plus any fixed broker fees. For investors using low-cost platforms, this can be a practical alternative to receiving dividends directly.
For long-term investors focused on growth, accumulation is usually better. It's also often more tax-efficient in the UK and EU. But for retirees or income-focused investors, distributions can make more sense.
Do ETFs Really Match the Index? Mostly, Yes.
ETFs aim to track their index closely, but they’re not perfect. There’s always a small gap. Here’s why:
Fees: Even low-cost ETFs charge something—usually 0.05% to 0.30% per year.
Tracking Error: Small differences in dividend handling, taxes, or rebalancing can affect returns.
Replication Method: Some ETFs physically hold all the stocks in the index. Others use financial contracts (synthetic replication). For most long-term investors, the difference is minor.
A well-run ETF might return 9.95% in a year where the index returns 10%. That’s close enough for most people.
Are ETFs Expensive? Not at All.
This is one of the best features of ETFs: they’re cheap.
Actively managed funds often charge 1% or more every year. A broad-market ETF might cost just 0.07%. That means more of the market’s return stays in your pocket.
And just to clear up a common concern: accumulating and distributing versions of the same ETF usually have the same fees. They’re just different share classes of the same fund.
If You’re in the UK or EU, You Might Hit a Wall
Here’s something most U.S.-based blogs don’t tell you:
If you're a retail investor in the UK or EU, you can’t buy U.S.-domiciled ETFs like SPY or VOO. They’re not available on most platforms.
Why? Regulation.
EU rules (PRIIPs) require a special document called a KID (Key Information Document) for ETFs sold to retail investors. U.S. ETFs don’t provide it, so they’re off-limits.
The workaround? UCITS ETFs—European-compliant funds that meet these requirements. They’re available on platforms like DEGIRO, Trading 212, IB and others.
Some examples:
SPY (U.S. ETF) – the most well-known S&P 500 ETF, but has slightly higher fees (0.0945%) and distributes dividends
VOO (U.S. ETF) – lower fee alternative from Vanguard (around 0.03%–0.05%), still unavailable in the UK/EU
VUSA (UCITS S&P 500 ETF, distributing) – available
CSP1 / CSPX (UCITS S&P 500 ETF, accumulating) – available in the UK and EU under different tickers depending on the exchange
Same index. Same strategy. Different wrapper.
So, What Should You Actually Do?
If you’re investing for the long run and want to track an index, ETFs are one of the best tools you can use.
Just make sure you:
Pick between distributing and accumulating, based on whether you want income now or growth over time
Understand what you’re tracking and how it’s built
Use UCITS ETFs if you're in the UK or EU
And check fees—they're small, but they matter
Once you understand how ETFs work, everything else in investing starts to make a lot more sense. And when you’re not guessing, you’re much more likely to stick to your plan.
Simple. Transparent. Effective. That’s what ETFs should be.
Coming Soon
In next week’s post, I’ll explore:
Why You Feel Bad When the Market Drops
The psychology of loss, volatility, and how to stay sane when markets turn manic
Until then, stay invested—and stay curious.
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