Home / Fund comparison
CSPX vs VOO
Both copy the S&P 500. The difference is where each fund is based, and that changes the tax on your dividends. Here is what the same monthly money did in each, depending on where you live.
The short answer
Same 500 companies, so the returns are almost identical before tax. VOO is cheaper. CSPX is based in Ireland, so the US takes 15% of its dividends instead of the 30% it takes from people in places without a US tax treaty, such as Singapore. In our sums for someone in Singapore, US$100 a month since October 2010 ended about US$1,500 higher in CSPX, mostly from the lower dividend tax. In a treaty country, the two finished almost level. Past results, not a forecast.
US$100 a month in CSPX and VOO
The share of each VOO dividend the US keeps before it reaches you. CSPX has 15% taken inside the fund, whoever you are.
Start
US dollars. Between 10 and 100,000.
You put US$0 into each. On 9 October 2026 they were worth
Real past prices. VOO dividends are cut by your rate and reinvested that month. CSPX reinvests inside the fund. Fund fees are already in the prices. No broker fees, no tax in your own country.
Side by side
| CSPX | VOO | |
|---|---|---|
| What it copies | The S&P 500 | The S&P 500 |
| Legal home | Ireland | United States |
| Where it trades | London, in US dollars | New York, in US dollars |
| Dividends | Kept in the fund and reinvested | Paid out to you every three months |
| US tax on dividends | 15%, taken inside the fund, wherever you live | 0% to 30%, depending on where you live |
| Yearly fee | 0.07% | 0.03% |
| US estate tax risk for non-US people | Generally no | Can apply above US$60,000 of US assets |
| Run by | iShares (BlackRock) | Vanguard |
The dividend tax is the whole story
The companies in the S&P 500 pay dividends. When those dividends leave the US, the US keeps a share.
If you hold VOO and you are not a US person, the US keeps 30% of each dividend, or less if your country has a tax treaty with the US. Singapore, Malaysia, Hong Kong and the UAE have none, so 30%. The UK, Australia and most of Europe have one, usually 15%.
CSPX is based in Ireland, which has a treaty with the US. So the US keeps 15% inside the fund, and that is the same for everyone who owns it.
The S&P 500 pays out roughly 1% to 2% of its value a year in dividends, so the difference is small each year. Over fifteen years of monthly buying it adds up, as the numbers above show.
The estate tax nobody mentions
If you are not a US citizen or resident and you die holding more than US$60,000 of US assets, your estate must file a US estate tax return and US estate tax can be due. Shares of a US-based fund such as VOO count. Shares of an Irish-based fund such as CSPX generally do not. Some countries have a treaty that changes this; Singapore does not. The US tax authority explains the rule.
Other differences
- Fee. VOO costs 0.03% a year and CSPX 0.07%. On US$10,000 that is US$3 against US$7.
- Price per unit. Both cost several hundred US dollars a unit, so small monthly amounts may need a broker that sells fractions, or saving up for a few months.
- Trading hours. CSPX trades in London hours, VOO in New York hours. From Singapore, London’s session runs in the afternoon and evening.
- US people. If you are a US citizen or resident, Irish funds like CSPX are usually not sold to you and the tax rules make them costly.
Questions
Is VUAA the same as CSPX?
Very close. VUAA is Vanguard’s Irish-based S&P 500 fund, also keeping dividends inside, also 0.07% a year. Our index calculator shows both.
Why start in October 2010?
Our London price record for CSPX starts in September 2010, the same month VOO began, so October is the first month both can be bought for a full month.
What about the tax in my own country?
Not included. Some countries tax dividends or gains again, and some let you claim back foreign tax. Check your own country’s rules.
Prices and dividends: Yahoo Finance month-end closes to 9 October 2026. Fees: iShares and Vanguard fund pages, read 11 October 2026. Treaty rates: US tax authority treaty tables. Fund names are examples to explain how fund location affects tax, not a suggestion to buy, sell or hold any of them. This is general information, not tax advice.
Read the full CSPX guide.
What CSPX owns, what it costs, and how buying it works.