When people ask how to buy STI, they almost never want to buy the index itself, because you can't. The Straits Times Index is just a list of Singapore's 30 biggest listed companies. What you actually buy is an STI ETF, a single fund that holds all 30 in roughly the right weights. There are two on the SGX: the SPDR STI ETF (ticker ES3) and the Amova Singapore STI ETF (ticker G3B, the old Nikko AM one). You can buy either through a normal brokerage, set up a monthly plan from S$100, or use CPF and SRS money. This guide walks the cheapest route for each, with the real 2026 fees.
The STI is an index, not a product. It tracks the 30 largest and most traded companies on the SGX, which together make up roughly 80% of the value of the Singapore market. The three local banks alone (DBS, OCBC, UOB) dominate the weighting, so an STI ETF is, in plain terms, a heavily bank-and-blue-chip Singapore-dollar fund.
An STI ETF (exchange-traded fund) is a fund that holds those 30 stocks and trades on the exchange like a single share. Buy one unit and you own a sliver of all 30. That is the whole appeal: instant diversification across the Singapore market in one trade, instead of buying DBS, OCBC, Singtel and 27 others separately. If the index terms are new to you, the ETF glossary entry and index fund definition cover the mechanics in a paragraph each.
Both funds track the same 30 stocks, so performance is near-identical. The real differences are cost, fund size (which affects how easily you can buy and sell), and when dividends land. Nikko AM rebranded its fund to Amova in 2025, so G3B is the same fund you may know as the Nikko AM STI ETF.
Figures below are from each fund's own pages and aggregators as of June 2026. Expense ratios and yields move, so treat them as 'around' figures and check the factsheet before you buy.
| SPDR STI ETF (ES3) | Amova STI ETF (G3B) | |
|---|---|---|
| Manager | State Street (SSGA) | Amova (formerly Nikko AM) |
| Expense ratio | around 0.28%-0.30% p.a. | 0.25% cap; 0.24% audited (FY to 30 Jun 2025) |
| Fund size (AUM) | around S$3.4 billion | around S$1.5 billion |
| Trailing dividend yield | around 3.3% | around 3.5% |
| Dividend months | February and August | January and July |
| Listed since | April 2002 | February 2009 |
For years the answer to 'what's the minimum to buy STI' was 100 units, a full board lot. That is no longer the binding number. Both STI ETFs now trade in very small lots: Amova's own fund page lists a board lot of 1 unit, and State Street cut the SPDR lot size from 100 units down to a handful too. With an ETF unit priced around S$5 in mid-2026, the floor to get started is now a few dollars, not several hundred.
What this means in practice: you no longer need to save up for a 'lot' before you start. You can buy a single unit, or use a monthly plan that buys fractional amounts. The old 100-unit hurdle that pushed beginners toward regular savings plans has mostly gone.
This is the standard route and the cheapest per dollar once you're investing meaningful amounts. You place a buy order on the SGX through a broker, the same way you'd buy a stock. The decision that actually matters is where your units are held: in your own CDP account, or in the broker's custody.
A CDP account registers the shares directly in your name with the Central Depository, so you are the legal owner and you receive dividends and notices directly. Custodian (custody) accounts hold the shares in the broker's name on your behalf, which is how most low-cost brokers work. Custody is cheaper and faster to open; CDP gives you direct ownership and survives any single broker shutting down. The CDP glossary entry explains the difference, and our guide to buying SGX stocks walks through placing the order itself.
An RSP debits a fixed sum each month and buys STI ETF units automatically, fractional units included. It is the hands-off way to dollar-cost average so you stop trying to time the market. The trade-off is a percentage fee that quietly eats into small amounts, so the cheapest plan depends on how much you invest.
All figures below are provider-published and current as of June 2026; RSP fees change often, so confirm on the provider's site. To see how a steady monthly habit compounds over 10 or 20 years, run the numbers in our compound interest calculator.
| Plan | Minimum / month | Fee | Holds units in |
|---|---|---|---|
| FSMOne ETF RSP | S$50 | around 0.08%, min S$1 (0% promos run periodically) | Custody |
| Phillip Share Builders (POEMS) | S$100 | 0.30% p.a. of holdings, min ~S$1, capped ~S$8.88 | CDP |
| OCBC Blue Chip Investment Plan | S$100 | 0.30% or S$5, whichever is higher | Custody |
| POSB Invest-Saver | S$100 | flat 0.82% per buy | Custody |
You can buy the STI ETF with money already sitting in your CPF Ordinary Account or your Supplementary Retirement Scheme account, not just cash. Both STI ETFs are approved under the CPF Investment Scheme (CPFIS-OA).
Using CPF-OA: you must keep the first S$20,000 in your OA untouched, and you can invest above that, subject to the CPFIS stock limit of 35% of your investible OA savings for shares and ETFs. Your OA otherwise earns 2.5% a year guaranteed, so only invest the portion you're comfortable putting at market risk. The CPFIS glossary entry and our CPFIS walkthrough cover the rules and the agent-bank account you'll need.
Using SRS: contributions are tax-deductible up to S$15,300 a year for citizens and PRs, and you can invest that SRS cash into the STI ETF the same way. It's a way to cut this year's income tax while still buying the market. Our SRS glossary entry explains the withdrawal rules before you lock money in.
If you're still deciding between doing this yourself and handing it to a robo-advisor, or whether the STI is even the right first fund versus a global index, our beginner's guide to investing in Singapore frames that choice.
Buying the STI is buying a concentrated bet. The three local banks make up a large chunk of the index, and the whole thing is one country, in one currency. That has paid off well recently, with the STI ETFs posting strong multi-year returns to 2026, but it is not the globally diversified core that most planners suggest as a foundation.
A common 2026 setup is to hold the STI ETF for Singapore-dollar dividends and home-market exposure, paired with a low-cost global or S&P 500 fund for the growth core. Dividends from the STI ETF are not taxed in your hands in Singapore, which is a genuine plus over many overseas-domiciled funds.
Very little in 2026. Both STI ETFs now trade in lots as small as 1 unit, and with a unit priced around S$5 you can buy a single share for a few dollars, though the brokerage minimum fee makes tiny buys inefficient. A regular savings plan lets you start from S$50-100 a month.
They track the same 30 stocks, so returns are near-identical. ES3 (SPDR) is larger and more liquid with tighter spreads; G3B (Amova) has the lower published expense ratio at a 0.25% cap and offers an accumulating class that reinvests dividends. For most buyers either is fine; pick on fee or liquidity preference.
Yes. Both STI ETFs are approved under CPFIS-OA, so you can invest CPF Ordinary Account savings above the first S$20,000, within the 35% stock limit. You can also invest SRS cash, which carries a tax deduction of up to S$15,300 a year for citizens and PRs.
No. Singapore does not tax dividends paid to individuals, so distributions from the STI ETF land in your account in full. ES3 pays in February and August, G3B in January and July; the accumulating GAB class reinvests instead of paying out, which suits long-term compounding.
This is general financial information for Singapore, not personal financial advice. Figures change — verify current rates against the official sources above before acting. See our full disclaimer.