Priya Raman, 27, is a data analyst earning $5,200 a month. After CPF contributions she takes home $4,160, spends $2,900 and has $24,000 in her savings account, with six months of spending already in Singapore Savings Bonds. She wants to invest $20,000 of the cash and then $500 a month, and every colleague she asks names a different exchange-traded fund (ETF).
The choice usually comes down to two index types. According to SGX (checked 30 September 2026), the Straits Times Index (STI) tracks the top 30 eligible companies listed on the Singapore Exchange, and its constituents are reviewed in March and September. A world index tracks listed companies in many countries, weighted by their market value.
Priya settles on 80% in a world fund and 20% in an STI fund, so her $20,000 starts as $16,000 and $4,000. Over 20 years of $500 a month, a fee gap of 0.4% a year costs her about $8,500. The sections below follow how she compares the two funds on holdings, tax, fees and custody, and whether to add CPF money.
What Does Each Index Hold?
An STI fund holds 30 Singapore companies. A world fund holds thousands of companies across developed and emerging markets, often through a fund listed in London.
| STI fund | World index fund | |
|---|---|---|
| Companies held | 30 | Thousands |
| Countries | Singapore | Developed and emerging markets |
| Usual trading currency | Singapore dollar | US dollar or another foreign currency |
| Dividends on Singapore shares | Not taxed | Not applicable |
| Foreign withholding tax | Little or none | Typically 15% on US dividends in an Irish-domiciled fund |
| Currency risk for a Singapore investor | None on the fund price | Yes |
Sources: SGX and IRAS
An STI fund concentrates the money in one market and a few sectors. A world fund spreads it more widely, and the investor takes on foreign currency movements in return. Priya already earns her salary and holds her CPF savings in Singapore, so she wants most of her investments spread abroad.
How Would Each Fund Be Taxed?
The Inland Revenue Authority of Singapore (IRAS) does not tax individuals on dividends from Singapore companies or on capital gains, according to its page on gains from shares and financial instruments (checked 30 September 2026). The tax on a world fund is collected abroad, before the dividend reaches the fund.
| $100,000 in a fund holding US shares, 2% dividend yield | US-domiciled fund | Irish-domiciled fund |
|---|---|---|
| Dividends a year | $2,000 | $2,000 |
| Typical withholding rate | 30% | 15% |
| Withheld a year | About $600 | About $300 |
Source: Typical treaty rates for funds; not an IRAS figure
On Priya's $16,000, at the same 2% yield, dividends would be $320 a year. A US-domiciled fund would lose about $96 of it, and an Irish-domiciled fund about $48. The gap grows with the balance.
A US-domiciled fund also counts as a US asset for estate tax. The US Internal Revenue Service (IRS) requires an estate tax return (checked 30 September 2026) when a non-US person dies holding more than US$60,000 of US-situated assets, which include stock of US companies. An Irish-domiciled fund is a company organised in Ireland, so Priya narrows her world fund choice to Irish-domiciled funds.
Read Also: How Investment Income Is Taxed In Singapore In 2026
What Would Fees Cost Her Over 20 Years?
An ETF charges an expense ratio each year, taken from the fund's value. On $50,000, a fund at 0.2% a year costs $50,000 × 0.2% = $100 a year, and a fund at 0.6% costs $300.
| $500 a month for 20 years, 5% a year before fees | Balance after 20 years |
|---|---|
| Expense ratio 0.2% a year (Priya's plan) | About $198,500 |
| Expense ratio 0.6% a year | About $190,000 |
| Difference | About $8,500 |
Source: Example; the return is an assumption, compounded monthly
Brokerage commissions are charged on each purchase and sale. A monthly purchase of $500 with a $10 minimum commission costs 2% of each purchase. Priya buys once a quarter and puts 3 × $500 = $1,500 into one fund at a time, so the same $10 is about 0.7% of each purchase. Each quarter she buys whichever fund is below its share of the mix.
Where Does She Hold The Units?
SGX-listed ETFs can be held in the investor's own account at the Central Depository (CDP), or in a broker's custodian account in the broker's name. A CDP account keeps the holding in the investor's own name. ETFs listed on overseas exchanges are held through the broker's custodian.
Priya's STI fund trades on SGX, so she holds it in her CDP account. Her London-listed world fund sits with her broker's custodian.
Which Mix Fits A 20-Year Horizon?
The mixes below show how investors combine the two index types with bonds. They are examples only, and the right mix depends on the investor's horizon and tolerance for falls.
| Example | World index fund | STI fund | Bonds, Savings Bonds or T-bills | Suits a horizon of |
|---|---|---|---|---|
| Growth (Priya) | 80% | 20% | 0% | Over 15 years |
| Balanced | 60% | 15% | 25% | 7 to 15 years |
| Cautious | 35% | 15% | 50% | 3 to 7 years |
Source: Examples only
Before any of these, investors usually keep several months of spending in cash, Savings Bonds or T-bills. Money needed within about three years does not belong in an equity fund, because the fund can be down when the money is needed. Priya's 6 × $2,900 = $17,400 in Savings Bonds stays outside the portfolio, and she has no large spending planned within 15 years, so she takes the growth mix.
Read Also: Singapore Savings Bonds Vs T-Bills Vs Fixed Deposits: Which Pays More In 2026?
Should She Add CPF Or SRS Money?
The Ministry of Finance (MOF) lists ETFs among the investments SRS money can buy, and returns inside SRS are not taxed before withdrawal. CPF Ordinary Account savings above $20,000 can buy approved ETFs under the CPF Investment Scheme (CPFIS).
CPF money comes with a hurdle. The CPF Board pays 2.5% a year on the Ordinary Account, so an ETF bought with it has to return more than 2.5% after fees and commissions before it adds anything. Priya has $41,000 in her Ordinary Account, so $21,000 could be invested. She leaves it at 2.5% while she learns how her cash portfolio behaves, and she has no SRS account.
Read Also: CPFIS: Limits, Fees And The 2.5% Return To Beat
Read Also: Track Your ETFs Alongside CPF And Cash In Cashmere Pocket
STI ETF Or World ETF: Which Suits Whom?
Priya puts $16,000 into an Irish-domiciled world fund and $4,000 into an STI fund. She then invests $1,500 a quarter to keep the 80:20 split. That is $500 a month of the $1,260 she has left each month after spending. Her remaining $4,000 in cash and $17,400 in Savings Bonds stay as her emergency fund.
A world index fund suits investors who want the widest spread of companies and accept foreign currency movements, and an Irish-domiciled one reduces the tax on US dividends. An STI fund suits investors who want Singapore dollar holdings and tax-free Singapore dividends, and it is often held beside a world fund. The split between them, and how much goes into bonds, depends on each investor's horizon, income and existing CPF and property holdings.