Round Lot in 2025: What Australian Investors Need to Know

When browsing the Australian share market, you’ll come across plenty of jargon—one phrase that still pops up, even as digital trading surges, is the ’round lot.’ While it might sound like a relic from an era of open-outcry trading floors, this concept continues to shape trading strategies, costs, and even your ability to access certain investments in 2025. Let’s break down why round lots still matter for everyday Aussie investors and what’s changed in the latest market environment.

What Is a Round Lot and Where Does It Still Matter?

A round lot typically refers to the standard trading unit for shares on a stock exchange. In Australia, that usually means 100 shares of a company. Anything less is called an ‘odd lot.’ Historically, exchanges and brokers set different rules, fees, and even trading privileges based on whether you were dealing in round lots or odd lots.

• Standardisation: Round lots make it easier to match buyers and sellers, ensuring liquidity and tighter bid-ask spreads.
• Brokerage Fees: Some brokers still structure fee tiers based on round or odd lot quantities, though this is less common than a decade ago.
• Access to IPOs: Initial public offerings and certain placements may require investors to apply in round lots, not odd lots, to participate.

While digital trading platforms have made odd-lot trading far easier, the round lot concept hasn’t disappeared entirely. The ASX, for example, continues to reference round lots in its trading rules, and many international exchanges use them to define ‘marketable parcels’ of shares.

Round Lot Trading in 2025: New Policies and Tech Shifts

Australian trading platforms have rapidly evolved in 2025, but round lots remain relevant thanks to several factors:

• Fractional Shares: Some platforms now let you buy less than one share, making odd lots and even micro-lots commonplace. However, not all ASX-listed shares are available in fractional units, and round lots are still needed for some corporate actions and voting rights.
• Brokerage Models: In early 2025, major discount brokers like SelfWealth and CommSec revised their fee schedules, eliminating most round-lot surcharges but still offering lower per-share pricing for larger, round-lot trades.
• Market Depth and Liquidity: For thinly traded stocks, round lots continue to see tighter spreads and faster fills, while odd-lot orders may be partially filled or executed at less favourable prices.

Recent ASX policy updates have also clarified settlement processes, with round lot transactions typically settled more quickly and with less administrative friction than a patchwork of odd-lot trades. This can be important for SMSF trustees and active traders seeking to optimise execution speed and certainty.

Real-World Examples: When Round Lots Make a Difference

Let’s look at how the round lot concept plays out for different Aussie investors in 2025:

• IPO Participation: When Woolworths spinoff W23 listed in early 2025, retail investors could only apply in multiples of 100 shares, with odd-lot applicants being scaled back or excluded from allocation.
• ETF Investing: While fractional ETF units are becoming available, certain popular funds like VAS and IOZ still require round-lot holdings to qualify for dividend reinvestment plans (DRPs).
• Trading Thinly-Listed Stocks: An investor buying 15 shares of a microcap mining explorer on the ASX may find their order sits unfilled for days, while a 100-share round lot trades instantly at the quoted price.

These scenarios highlight how round lots can impact everything from access and execution to cost and portfolio management. If you’re investing through an SMSF or trading regularly, understanding round lot implications could mean the difference between a smooth transaction and a frustrating delay.

The Bottom Line: Should Round Lots Influence Your Strategy?

While modern trading platforms have made it easier to buy and sell in any quantity, round lots remain a core building block of the Australian share market. For most blue-chip shares, odd-lot trading is now seamless and cost-effective. However, if you’re participating in IPOs, DRPs, or trading less liquid stocks, sticking to round lots could still save you money and hassle in 2025.

Always check your broker’s current policies and the latest ASX rules—especially if you’re scaling up your investment activities or planning to participate in new listings. By understanding where round lots matter, you’ll be better positioned to optimise your trades and reduce unnecessary friction in your portfolio.