CSPX vs VOO: Which Is Better for Singapore Investors? (2026)

A data-driven comparison of CSPX (LSE) and VOO (NYSE) — withholding tax, estate tax, total costs, and which wins for Singapore investors in 2026.

For Singapore investors, CSPX wins over VOO on two critical factors: withholding tax (15% vs 30% on US dividends) and US estate tax exposure (none for CSPX vs a 40% tax on holdings above USD 60,000 for VOO). VOO’s lower expense ratio (0.03% vs 0.07%) is real but small — the WHT difference costs you 4–5 times more annually. CSPX on the London Stock Exchange is the correct choice for most Singapore-based S&P 500 investors.

Not financial advice. All figures are for educational reference only. Data as at Q1 2026 unless noted.

Table of Contents

Quick Answer: CSPX or VOO?

Buy CSPX. For Singapore tax residents investing in S&P 500 exposure, CSPX (iShares Core S&P 500 UCITS ETF, listed on the London Stock Exchange) is substantially more tax-efficient than VOO (Vanguard S&P 500 ETF, listed on the New York Stock Exchange). The primary reason: CSPX is domiciled in Ireland and benefits from the Ireland-US double tax treaty, which reduces withholding tax on US dividends from 30% to 15%. VOO is domiciled in the US and pays the full 30% WHT to non-US investors. Additionally, VOO exposes Singapore investors to US estate tax risk on holdings above USD 60,000 — a risk that does not apply to CSPX.

The only advantage VOO has is a slightly lower expense ratio (0.03% vs 0.07% for CSPX). However, this 0.04% difference is dwarfed by the 15% WHT saving on dividend income. At the S&P 500’s current yield of approximately 1.3%, the WHT saving alone is worth approximately 0.195% per year on your total portfolio value — nearly five times the TER disadvantage. See the CSPX ETF Singapore complete guide for a deeper breakdown of how this ETF works and how to buy it.

Key Differences at a Glance

Source: iShares and Vanguard fund factsheets, Q1 2026. AUM figures approximate as of Q1 2026.

Tax & Cost Comparison: The Main Differentiator

The biggest cost difference between CSPX and VOO for Singapore investors is not the expense ratio — it is withholding tax (WHT) on US dividends. This is the single most important factor, and it is one that many online comparison articles fail to highlight clearly.

How withholding tax works: When US companies in the S&P 500 pay dividends, the US Internal Revenue Service (IRS) withholds a portion of those dividends before they reach the ETF. For VOO, which is domiciled in the United States, the withholding tax on dividends received by the fund is 0% — but this is misleading, because the 30% withholding then applies when dividends are paid out to non-US investors at the investor level. For CSPX, domiciled in Ireland, the Ireland-US tax treaty means the fund pays only 15% WHT to the IRS before dividends reach the fund. Singapore investors holding CSPX do not pay any additional Singapore personal tax on those dividends.

The practical result: CSPX retains 85 cents of every USD 1.00 of dividends received from US stocks; VOO (for Singapore investors) effectively retains only 70 cents. Over a large portfolio or a long time horizon, this 15-percentage-point difference is substantial.

Source: The Kopi Notes calculation, Q1 2026. WHT calculated on ~1.3% S&P 500 trailing dividend yield. SGD/USD assumed at 1.35. Figures illustrative; actual savings depend on yield at time of holding. Not financial advice.

US Estate Tax: A second major risk for Singapore investors holding VOO is the US federal estate tax. Under current US law (IRS Publication 559), non-resident aliens (including Singapore citizens and permanent residents) who hold US-situs assets — which includes shares in US-domiciled ETFs like VOO — are subject to US estate tax on amounts above USD 60,000 at rates up to 40%. This threshold has not been adjusted for decades. A Singapore investor with SGD 300,000 invested in VOO (approximately USD 222,000) could face US estate tax of up to USD 60,000+ on their estate. CSPX, being domiciled in Ireland and traded on the LSE, is not a US-situs asset and carries no US estate tax risk for Singapore investors. For a detailed explanation of this risk, see our guide to US estate tax for Singapore investors.

Historical Performance Comparison

Because both CSPX and VOO track the identical index — the S&P 500 — their gross performance (before costs and taxes) is essentially identical. Any small differences in reported returns are due to timing of dividend reinvestment, tracking error, and FX effects on the trading price vs NAV.

Over the 10 years to December 2025, the S&P 500 delivered approximately 13.1% p.a. in USD total returns. Both CSPX and VOO closely track this benchmark. iShares reports CSPX tracking difference of approximately -0.03% (meaning CSPX actually outperforms its benchmark slightly, a sign of excellent securities lending revenue). VOO’s tracking difference is also negligible given its scale.

The net-of-tax performance for a Singapore investor, however, diverges due to the WHT differential. A Singapore investor in CSPX keeps 85% of dividends; a Singapore investor in VOO keeps only 70% of dividends. Over a 10-year period with a 1.3% annual yield and reinvestment, this compounds to a meaningful advantage for CSPX even before considering the TER difference.

Total Cost of Ownership (TER + WHT + Transaction Costs)

When comparing ETFs, the “total cost of ownership” for a Singapore investor includes three components: the TER, the effective withholding tax drag, and transaction costs (brokerage fees, FX spread). Let us work through each for a SGD 100,000 investment:

TER: CSPX costs 0.07% p.a. = SGD 70 per year. VOO costs 0.03% p.a. = SGD 30 per year. Advantage: VOO by SGD 40/year.

WHT drag: At a 1.3% S&P 500 dividend yield, CSPX’s 15% WHT costs approximately SGD 195/year in foregone returns. VOO’s 30% WHT costs approximately SGD 390/year. Advantage: CSPX by SGD 195/year.

Transaction costs: Both trade in USD on their respective exchanges. Buying VOO on NYSE through a Singapore broker may face currency risk, but most platforms offer USD accounts. There is no material difference here for investors using platforms like Interactive Brokers. CSPX trades in USD on the LSE (there is also a GBP-denominated class). For brokers that offer both, transaction costs are broadly comparable.

Net advantage (per SGD 100,000/year): CSPX saves SGD 195 on WHT but costs SGD 40 more in TER = net annual advantage of SGD 155 per SGD 100,000 invested. Over 20 years with reinvestment at 7% p.a., this difference compounds to approximately SGD 7,000–9,000 on a SGD 100,000 starting position. On a SGD 500,000 position, the compounded saving exceeds SGD 35,000.

If you are building towards early retirement or managing a large portfolio, the Singapore retirement calculator can help you model how these savings affect your projected retirement date and required nest egg.

To maximise cost efficiency, use a low-commission broker. moomoo Singapore offers competitive fees and is popular for ETF investing. For SRS-compatible investing, FSMOne provides access to both CSPX and a range of other LSE ETFs through SRS accounts. The Syfe referral code grants access to commission-free ETF trading for beginners.

Who Should Pick Which?

CSPX is the right choice if:

• You are a Singapore tax resident building long-term S&P 500 exposure through DCA or lump sum
• Your investable portfolio in this fund exceeds SGD 30,000 (at which point the WHT saving materially outweighs the TER disadvantage)
• You want to avoid US estate tax risk — particularly important for portfolios above SGD 80,000
• You prefer an accumulating structure (dividends reinvested automatically, no need to manually reinvest quarterly cash)
• You hold other Ireland-domiciled ETFs (VWRA, IWDA) and want consistency in your portfolio structure

VOO might be considered if:

• You already have an established US brokerage account and trade primarily on NYSE/NASDAQ
• You are a US person (US citizen, Green Card holder) — in which case the WHT comparison is entirely different, and VOO may be more appropriate
• Your total portfolio in this asset class is very small (below SGD 10,000) and the absolute dollar saving from CSPX is negligible

For the overwhelming majority of Singapore retail investors building ETF portfolios for retirement or financial independence, CSPX is the correct instrument. The tax efficiency advantage is permanent and structural — it is not dependent on future policy changes, and it compounds with every passing year. Pairing CSPX with a global equity ETF like VWRA (for rest-of-world exposure) is a popular two-ETF strategy among Singapore investors seeking broad market exposure at low cost.

For income-seeking investors who want both ETF growth and regular cash distributions alongside their equity ETFs, our guide to passive income in Singapore covers how to blend S-REITs, dividend stocks, T-bills, and ETFs into a portfolio that generates regular cash flow. Additionally, the CPF investment strategy guide explains how CSPX fits into your overall CPF-SRS-cash portfolio structure.

Disclaimer: This article is for educational purposes only and is not financial advice. All figures are illustrative. Tax treatment depends on your individual circumstances. Always consult a licensed financial adviser before making investment decisions. Data as at Q1 2026.

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