Table of Contents
1. What Is It?
2. How It Works in Singapore
3. Key Considerations
4. Worked Example
5. Frequently Asked Questions
This article is for informational purposes only and does not constitute financial advice. Please conduct independent research before making investment decisions.
Market capitalisation is one of the most fundamental metrics in stock investing — yet many Singapore retail investors treat it as just a size indicator without understanding its full implications for liquidity, index inclusion, and valuation. Here’s what you need to know.
What Is It?
Market Cap Formula:
Market Capitalisation = Share Price × Total Shares Outstanding
Example: DBS Group Holdings trades at $38.50 per share with approximately 2.57 billion shares outstanding. Market cap = $38.50 × 2.57B = ~$98.9 billion SGD (as at Q1 2026).
Size categories on SGX (approximate):
- Large-cap: >SGD 1 billion — the 30 STI constituents, major S-REITs, and blue chips
- Mid-cap: SGD 200 million – SGD 1 billion — established companies with decent liquidity
- Small-cap: <SGD 200 million — higher risk, often illiquid, speculative
How It Works in Singapore
SGX’s Straits Times Index (STI) is a market-cap-weighted index of the 30 largest and most liquid companies listed on the mainboard. Companies are ranked by free-float market cap — the market cap of shares actually available for public trading (excluding locked-up shares held by controlling shareholders).
When a company’s market cap crosses certain thresholds, it becomes eligible for STI inclusion, which triggers significant passive fund buying (STI ETFs must hold all 30 constituents). This is why index inclusion events often cause price jumps.
SGX’s largest companies by market cap (approximate, Q1 2026):
- DBS Group: ~SGD 98B
- OCBC Bank: ~SGD 56B
- UOB: ~SGD 45B
- Singapore Telecommunications (Singtel): ~SGD 30B
- CapitaLand Investment: ~SGD 14B
The Singapore banking trio (DBS, OCBC, UOB) alone account for a very large proportion of the STI’s total market cap, making the STI heavily bank-weighted. This is why the STI ETF effectively gives you concentrated exposure to Singapore’s banking sector.
Key Considerations
Market cap ≠ valuation: A large market cap doesn’t mean a stock is “expensive” or “cheap.” A $1 billion company could be overvalued or undervalued depending on earnings. Market cap tells you the aggregate market consensus on value — not whether that consensus is correct.
Float-adjusted vs. total market cap: For index purposes, free-float market cap (excluding shares held by controlling shareholders, government entities, etc.) is more relevant. Many Singapore companies have large strategic shareholders (Temasek holdings, family shareholders), reducing the effective free float.
Liquidity implications: Large-cap stocks are highly liquid — you can buy and sell millions of dollars worth without moving the price. Small-cap stocks may have very thin daily volume, making it hard to enter or exit positions at fair prices.
Market cap for REITs: For S-REITs, market cap = unit price × total units outstanding. Larger S-REITs (CICT at ~SGD 14B market cap) have better access to capital markets, lower borrowing costs, and more institutional investor coverage. Smaller S-REITs may offer higher yields but with liquidity and governance trade-offs.
Worked Example
Suppose you’re comparing two SGX-listed companies:
Company A: Share price $2.00, 500 million shares outstanding → Market cap = $1.0B (large-cap)
Company B: Share price $0.50, 100 million shares outstanding → Market cap = $50M (small-cap)
Company A is 20x larger by market cap despite having a higher share price. It’s likely in more indices, has more analyst coverage, and is more liquid.
For an index investor buying the STI ETF, you automatically get market-cap-weighted exposure — more DBS, OCBC, and UOB; less of the smaller STI constituents. This is worth understanding when assessing STI ETF concentration risk.
See our related guides on free float, blue chip stocks in Singapore, and our REITs vs ETF comparison for how market cap influences portfolio construction decisions.
Frequently Asked Questions
How is market capitalisation calculated?
Market cap = Share Price × Total Shares Outstanding. For example, a stock trading at $5.00 with 200 million shares has a market cap of $1 billion SGD.
What is considered large-cap in Singapore?
On SGX, companies with market cap above SGD 1 billion are generally considered large-cap. The STI’s 30 constituents are all large-caps, with the three banks (DBS, OCBC, UOB) being the biggest.
Does a higher share price mean a larger company?
No. A company with a share price of $0.10 and 10 billion shares has a market cap of $1 billion — the same as a company with a price of $10 and 100 million shares. Market cap, not price, measures size.
What is free-float market capitalisation?
Free-float market cap counts only shares available for public trading, excluding those held by controlling shareholders, governments, or long-term strategic investors. This is used for index weighting (STI, MSCI) as it better reflects the investable universe.
How does market cap affect Singapore REIT investing?
Larger S-REITs generally have better access to equity and debt capital markets, lower borrowing costs, and stronger institutional backing. Smaller REITs may offer higher yields but with less liquidity and potentially weaker governance.
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