Odd Lot Trading Singapore: Buying and Selling Shares in Quantities Below a Full Board Lot

How odd lot trading works on SGX, why it costs more than board lot trading, and when Singapore investors use it deliberately.

Last updated: October 2026

Odd lot trading is the buying or selling of shares in a quantity that is not a whole multiple of the exchange’s standard board lot size — on SGX, any amount other than a multiple of 100 shares — executed through a separate matching mechanism from the main order book.

Not financial advice. All figures for educational reference only. Data as at October 2026.

What Is Odd Lot Trading?

Odd lot trading refers to buying or selling shares in a quantity other than a whole multiple of the exchange’s standardised board lot size. On the Singapore Exchange, where the standard board lot is 100 shares, any order for a quantity that isn’t an exact multiple of 100 — such as 45 shares, or 230 shares which contains a 30-share odd-lot component — falls under odd lot trading.

Because SGX’s main central order book is built around board lot quantities for liquidity and price-matching efficiency, odd lots are handled through a separate mechanism, typically involving designated market makers or a distinct matching system that pairs odd lot buyers and sellers. This separation generally results in wider bid-ask spreads and sometimes slower execution compared to standard board lot trades on the primary order book.

Odd lots arise in two main ways: deliberately, when an investor chooses to buy or sell a non-standard quantity (often to manage limited capital or fine-tune a position), and incidentally, as a byproduct of corporate actions like rights issues, bonus share issues, or share consolidations that do not divide evenly into whole board lots for every shareholder.

How Does It Work in Singapore?

In Singapore, most major brokerages support odd lot trading as a distinct order type alongside standard board lot orders, often clearly labelled to help investors understand they are accessing a different, typically less liquid, part of the market. Pricing for odd lot orders is generally derived from — but less favourable than — the prevailing board lot bid-ask spread, reflecting the reduced liquidity and the cost to market makers of facilitating smaller, less standard trades.

Investors with limited capital sometimes use odd lot trading deliberately to diversify across more stocks than they could afford if restricted to full board lots. For example, an investor with SGD 2,000 wanting exposure to a SGD 50 stock could buy 40 shares (an odd lot) for SGD 2,000, rather than needing SGD 5,000 for a full 100-share board lot.

Source: General SGX odd lot trading mechanics, illustrative scenarios.

Worked Example

A Singapore investor holds 100 shares of a REIT purchased as one board lot. The REIT later announces a 1-for-5 rights issue, entitling the investor to 20 additional shares, bringing their total holding to 120 shares — composed of one full board lot (100 shares) plus a 20-share odd lot.

If the investor wants to sell their entire position, they would typically execute two separate trades: a standard board lot sale of 100 shares at the prevailing bid price on the main order book, and a separate odd lot sale of the remaining 20 shares, likely at a slightly less favourable price due to the odd lot mechanism’s wider spread — a common, if minor, friction point investors encounter after corporate actions that don’t divide evenly.

Advantages of Odd Lot Trading

Enables precise position sizing. Investors with limited capital can buy the exact dollar amount they want, rather than being forced to round up to the nearest full board lot.

Supports broader diversification. Odd lot trading makes it feasible to hold small positions across more stocks than would be affordable buying only in full board lots.

Allows disposal of leftover shares. Investors left with odd lots after corporate actions can still liquidate those shares rather than being stuck holding an awkward, illiquid quantity.

Widely available through brokers. Most Singapore brokerage platforms provide a straightforward odd lot order type, so investors don’t need special arrangements to access it.

Useful for topping up to a round number. Investors can use odd lot orders to add a small number of shares to round an existing holding up to a clean board lot multiple.

Risks and Limitations

Wider bid-ask spreads. Odd lot trades typically execute at less favourable prices than the equivalent board lot trade, representing a real, if often small, cost.

Lower liquidity. Fewer market participants are actively quoting odd lot prices compared to the deep liquidity of the main board lot order book, which can make execution slower or less predictable.

Not all brokers handle odd lots identically. Pricing mechanisms, fees, and execution speed for odd lot trades can vary meaningfully between brokerage platforms.

Can incur disproportionate transaction costs. Flat brokerage fees on a small odd lot trade can represent a much higher percentage cost than the same fee on a larger board lot trade.

Administrative friction after corporate actions. Investors may need to actively manage and separately trade away small odd lot remainders rather than having them automatically consolidated.

Odd Lot Trading vs Fractional Share Investing

Source: General market structure comparison.

The Bottom Line

Odd lot trading gives Singapore investors a practical way to buy, sell, and manage share quantities outside the standard 100-share board lot — useful for precise position sizing or clearing out leftover shares from corporate actions — but it comes with a real, if usually modest, cost in the form of wider spreads and lower liquidity than board lot trades.

Frequently Asked Questions

Related Terms

• SGX Board Lot Size Singapore
• Odd Lot Shares from Corporate Actions Singapore
• Settlement Date (T+2) Singapore
• Good-Til-Cancelled (GTC) Order Singapore

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