Board Lot vs Odd Lot: How SGX Share Trading Units Work in Singapore
A board lot is the standard trading unit on the Singapore Exchange (SGX), historically 100 shares for most stocks, while an odd lot is any quantity smaller than a full board lot, traded on a separate Unit Share Market with typically wider spreads and lower liquidity.
Not financial advice. All figures for educational reference only. Data as at July 2026. Last updated: July 2026.
Key Takeaways
- SGX’s standard board lot size has been 100 shares since 2015, down from the older 1,000-share standard.
- From 5 October 2026, SGX RegCo began reducing board lot sizes further for selected higher-priced stocks: to 10 units for shares priced above S$10 up to S$100, and to 1 unit for shares priced above S$100.
- Odd lots (quantities below the standard board lot) trade on SGX’s separate Unit Share Market, which generally has lower trading volume and wider bid-ask spreads than the main board lot market.
- Trading odd lots often costs more per share in brokerage fees and less favourable pricing compared to trading in full board lots.
- The board lot size reduction is a deliberate SGX RegCo initiative to make higher-priced blue-chip stocks more affordable and accessible to retail investors.
What Are Board Lots and Odd Lots?
Stock exchanges standardise the minimum tradable quantity of shares to keep the main market orderly and liquid — this standard unit is called a board lot. On SGX, buying “1 lot” of a stock has historically meant buying 100 shares of it, since the board lot size was reduced from 1,000 to 100 units in January 2015 to make shares more affordable for retail investors.
An odd lot is any quantity of shares that isn’t a multiple of the standard board lot — for example, buying 37 shares of a stock with a 100-share board lot. Odd lots trade on a separate venue called the Unit Share Market, distinct from SGX’s main “ready market” where board lots trade.
The distinction matters because the two markets have different liquidity characteristics: board lot trading tends to have tighter spreads and more buy/sell interest, while odd lot trading can be thinner, meaning your buy or sell order may not get filled as quickly or at as favourable a price.
How Do Board Lots and Odd Lots Work on SGX?
SGX RegCo has been actively reducing board lot sizes further to improve retail accessibility to higher-priced stocks. Starting 5 October 2026, SGX reduced the standard board lot size for selected instruments priced above S$10: to 10 units for stocks priced between S$10 and S$100, and to just 1 unit for stocks priced above S$100. This change is reviewed and can be adjusted quarterly, initially applying to a first batch of stocks that together represented a significant share of trading activity.
| Feature | Board Lot Market | Odd Lot (Unit Share) Market |
|---|---|---|
| Standard unit | 100 shares (or 10/1 units for select high-priced stocks from Oct 2026) | Any quantity below the board lot size |
| Liquidity | Higher — main trading venue | Lower — thinner order book |
| Bid-ask spread | Typically tighter | Typically wider |
| Brokerage cost impact | Standard commission applies | Some brokers apply minimum fees regardless of lot size, making odd lots costlier per share |
| Best suited for | Investors buying a full board lot’s worth of capital | Investors with smaller capital or wanting precise share counts |
This board lot reduction directly addresses a long-standing retail access problem: a high-priced blue-chip stock trading at, say, S$35 per share would previously require S$3,500 to buy just one 100-share board lot. Under the reduced 10-unit board lot, the same stock becomes accessible for around S$350.
Source: Singapore Exchange Regulation (SGX RegCo) circulars on standard board lot size reduction, effective 5 October 2026; SGX market rules.
Board Lot vs Odd Lot Example
Before the October 2026 changes, a retail investor wanting to buy a stock trading at S$28 per share would need to purchase a full board lot of 100 shares, requiring S$2,800 in capital (plus brokerage fees) if trading only in board lots. If she only had S$1,000 to invest, she could instead buy 35 shares as an odd lot — but this trade would execute on the Unit Share Market, potentially at a slightly less favourable price and with a brokerage fee that doesn’t scale down proportionally for the smaller trade size.
After the reduced board lot size takes effect for that stock (assuming it’s priced between S$10–S$100 and included in the reduction), the standard board lot becomes just 10 shares, so she can buy a full board lot for S$280, on the main, more liquid market, with better pricing than before.
Advantages of Understanding Board Lots and Odd Lots
Better cost planning. Knowing a stock’s board lot size upfront helps you calculate the minimum capital needed for a “clean” trade on the main market.
Access to high-priced stocks. The reduced board lot sizes taking effect from October 2026 make previously expensive blue-chip stocks accessible with much smaller capital outlays.
Avoiding unnecessary odd lot costs. Understanding the odd lot market’s typically wider spreads helps investors decide whether to save up for a full board lot instead of trading in odd quantities.
Useful for precise portfolio sizing. Odd lot trading, despite its costs, allows more exact position sizing when a full board lot would overweight a single stock in a smaller portfolio.
Risks and Limitations
Wider spreads on odd lots. Because the Unit Share Market has less liquidity, buying or selling odd lots can mean a less favourable execution price than the equivalent board lot trade.
Minimum brokerage fees don’t scale down. Many brokers charge a flat minimum commission regardless of trade size, making small odd lot trades proportionally more expensive per share.
Board lot sizes can change. With SGX RegCo’s quarterly review process now actively reducing board lot sizes for select stocks, investors should check the current board lot size for a specific stock rather than assuming it’s always 100 shares.
Not all stocks are affected equally. The board lot reduction initially applies only to selected higher-priced instruments, so many SGX stocks still trade in the standard 100-share board lot.
The Bottom Line
Board lots remain the default, more liquid way to trade SGX shares, but Singapore’s 2026 board lot size reductions are steadily narrowing the gap for high-priced stocks — always check a stock’s current board lot size before trading, and be mindful that odd lot trades on the Unit Share Market usually come with a liquidity and cost trade-off.
Frequently Asked Questions
What is a board lot on SGX?
A board lot is the standard trading unit for a stock on the Singapore Exchange, historically 100 shares for most stocks since 2015, though select higher-priced stocks now have smaller board lots of 10 or 1 unit from October 2026.
What is an odd lot?
An odd lot is any share quantity smaller than the standard board lot size, traded on SGX’s separate Unit Share Market rather than the main board lot market.
Why did SGX reduce board lot sizes in 2026?
SGX RegCo reduced board lot sizes for selected higher-priced stocks, starting 5 October 2026, to lower the capital needed to trade a full lot and improve retail investor accessibility to blue-chip shares.
Is it more expensive to trade odd lots than board lots?
Often, yes. Odd lots trade on a less liquid market with typically wider bid-ask spreads, and many brokers apply a minimum commission that doesn’t scale down for smaller trade sizes, making the cost per share higher.
How do I know a stock's current board lot size?
Your broker’s trading platform will display the board lot size for each stock, and SGX periodically publishes circulars listing any board lot size changes following its quarterly review process.