VUAA and CSPX both track the S&P 500, both charge 0.07% a year, and both are Irish-domiciled accumulating funds. The honest answer to "which one?" is that there's almost nothing to choose between them — so the decision comes down to which line your broker quotes cheaper, not which fund is better.
What they share
Both are Irish-domiciled UCITS ETFs that fully and physically replicate the S&P 500 — VUAA from Vanguard, CSPX from iShares — holding all 500 constituents at index weights rather than a sample. Both accumulate dividends, so there's nothing to reinvest or declare. Both charge 0.07% — the CSPX factsheet has the full cost breakdown. And because both are domiciled in Ireland, a Euro investor gets identical withholding-tax treatment on the underlying US dividends. That accumulating structure also means neither fund pays out a distribution you'd have to declare each year — the dividends compound inside the wrapper, the same way in both. On every axis that compounds your money — fee, structure, tax wrapper, and the basket itself — they're the same fund wearing two brands.
Where they differ
Start with what doesn't differ: the holdings. Both own the same 500 companies at the same weights, because both fully replicate the same index. Here's VUAA's top ten — CSPX's is line-for-line identical:
| Ticker | Name | Weight |
|---|---|---|
| NVDA | NVIDIA Corp | 7.55% |
| AAPL | Apple Inc | 6.64% |
| MSFT | Microsoft Corp | 4.90% |
| AMZN | Amazon.com Inc | 3.62% |
| GOOGL | Alphabet Inc Class A | 2.98% |
The top five — NVIDIA, Apple, Microsoft, Amazon, Alphabet — come to 25.7% of the basket in either fund (as of 2026-03-31). A returns chart would just show two lines sitting on top of each other, which is why there isn't one here: same index, same replication, same fee means the same performance to within a rounding error.
This is why the question comes up at all. Open Trade Republic, Scalable, or Interactive Brokers and you'll often see VUAA and CSPX listed side by side — two S&P 500 accumulating ETFs at the same headline fee, with no obvious reason to prefer one. There's no hidden catch. The index is the same, both managers track it by holding the real shares, and so the only real differences are at the edges.
The first edge is the brand and the plumbing behind it. VUAA comes from Vanguard, which is owned by its own funds and, through them, by investors — the structure Vanguard uses to justify relentlessly low fees. CSPX comes from iShares, BlackRock's ETF arm and the largest ETF franchise in the world. Neither ownership model changes your 0.07%, but if you hold a deliberate preference for Vanguard's mutual structure, that's a legitimate tie-breaker.
The second edge is age and size. CSPX launched in May 2010; VUAA only arrived in May 2019. That nine-year head start has made CSPX one of the largest S&P 500 trackers in Europe, with the deeper on-exchange liquidity that comes with scale. For a buy-and-hold saver the gap is academic — both funds are enormous and going nowhere — but if you trade in size or chase the tightest spreads, CSPX's scale is a marginal point in its favour.
The third edge is the one you'll actually feel: listings. VUAA trades on Xetra in euros and on the London Stock Exchange in dollars (as VUAG); CSPX lists in dollars and sterling in London and in euros on Xetra (as SXR8). Which venue and currency your broker offers commission-free — and at the tighter spread — is the difference that touches your return. The listing currency itself is cosmetic: both funds hold US stocks, so your real exposure is effectively 100% USD whichever line you buy.
Who each one is for
For almost everyone the rule is simple: buy whichever your broker offers cheapest. If both trade commission-free at similar spreads, it's a coin-flip, and brand preference is a perfectly good way to break the tie — Vanguard's investor-owned structure for VUAA, or iShares' longer track record and scale for CSPX.
There's no reason to own both. They're the same 500 stocks; holding them side by side just doubles your S&P 500 weight under two tickers without adding anything. Pick one and move on.
And if you're not sure an S&P 500 tracker is the right core in the first place, that's the bigger question — VUAA vs VWCE, S&P 500 against a global all-world fund, is the comparison worth reading before this one.