S&P 500 UCITS ETFs compared (CSPX vs VUAA): costs, size, index, trading
Published: 2026-05-15
If you want simple US equity exposure in Europe, two accumulating UCITS ETFs show up again and again:
- CSPX (iShares), and
- VUAA (Vanguard).
Both aim to do the same job: give you S&P 500 exposure in a UCITS wrapper. For most long-term investors, either one can be a perfectly fine choice. The key is to compare them with a calm checklist and then commit — not to keep switching.
What is the same (the big picture)
- Same market: US large-cap equities (S&P 500).
- Very similar diversification: 500-ish companies, market-cap weighted.
- Similar risk: you’re taking US equity risk; the name on the ETF is not the main driver.
What can differ (the checklist that actually matters)
1) Accumulating vs distributing (check you’re comparing the right share class)
Many ETFs have multiple share classes. Make sure you are comparing accumulating with accumulating (or distributing with distributing). CSPX and VUAA are commonly used in accumulating form, but always confirm on your broker screen.
2) Total cost in practice: TER vs tracking difference
The headline TER is a useful first check, but what matters more is the ETF’s tracking difference (how far it lags the index after all costs and implementation details). Two ETFs with the same TER can still track slightly differently.
Calm rule: if both funds are large and reputable, the long-run differences here are usually small. Don’t over-optimize tiny decimals.
3) Fund size and liquidity (spreads + how easy it is to trade)
In practice, many investors choose the ETF that is more liquid on their exchange, because that often means:
- tighter bid–ask spreads,
- more consistent pricing, and
- fewer "weird" moments during volatile sessions.
4) Exchange listing and trading currency (this trips beginners up)
An ETF can have multiple listings. You might see CSPX/VUAA on different exchanges (LSE, Xetra, etc.) and in different trading currencies (USD, EUR, GBP).
Important: the trading currency is not the same thing as your underlying exposure. S&P 500 exposure is still largely USD-driven. But your broker can charge FX fees when you buy/sell, so trading currency can affect costs.
5) Index / implementation details (usually a non-issue here)
For CSPX vs VUAA, the underlying index exposure is the S&P 500. That means you usually don’t have the “different index family” problem — unlike comparisons such as MSCI vs FTSE for global funds.
A simple decision framework
- Pick the accumulating share class you actually want.
- Prefer the one your broker offers cheaply (lower commission + lower FX friction).
- Prefer the more liquid listing you can buy easily (often tighter spreads).
- Then stop revisiting the choice. Your savings rate and time horizon matter more.
Bottom line: CSPX vs VUAA is a good “problem” to have — both are mainstream UCITS options. Choose the one that is cheapest and simplest for you to hold for 10+ years.