Register For Our Mailing List

Register to receive our free weekly newsletter including editorials.

Why Australia has missed out on the “small cap effect”

Introduction

The idea that smaller companies offer higher risk-adjusted returns than larger companies, a claimed phenomenon known as the “small cap effect,” continues to live rent-free in the collective mind of Australian investors.

The size effect was first coined in Rolf W. Banz’s seminal 1981 paper “The relationship between return and market value of common stocks.” 1 Banz asserted that smaller firms, which he defined as the smallest 20% of the universe by market capitalisation, have higher risk adjusted returns, on average, than larger firms. Banz also found little difference in returns between medium sized and large sized firms.

But, for an investor, is the concept all it’s cracked up to be? Namely, does Banz’s concept of the small cap effect hold water in the Australian market?

There are currently 2,400 firms listed in the ASX. If an index was to be created on the ASX using Banz’s definition of a small firm, the largest constituent would be roughly A$8m in market capitalisation. In contrast, the smallest company in the ASX small ordinaries index currently is $200m in market capitalisation; and some of the largest constituents are larger than A$10b in market capitalisation. Perhaps unsurprisingly, the experience of an in investor in the ASX small ordinaries index has persistently bore no resemblance to the stellar returns depicted by Banz.

While many investors in Australia take a decision to structurally overweight small cap stocks given the sector and stock concentration in the large cap index, our analysis suggests that a separate allocation to small caps isn’t necessarily the best or most cost effective way to achieve this.

This paper will make the case that the performance, risk and constituent characteristics of the small cap index in Australia are poor; that the small cap designation is itself a misnomer (at least as it pertains to Australia); and the consequent benefit of investing in an unconstrained fund that can play the entire ASX.

Download the full paper

banner

Most viewed in recent weeks

Raising the GST to 15%

Treasurer Jim Chalmers aims to tackle tax reform but faces challenges. Previous reviews struggled due to political sensitivities, highlighting the need for comprehensive and politically feasible change.

Which generation had it toughest?

Each generation believes its economic challenges were uniquely tough - but what does the data say? A closer look reveals a more nuanced, complex story behind the generational hardship debate. 

100 Aussies: seven charts on who earns, pays, and owns

The Labor government is talking up tax reform to lift Australia’s ailing economic growth. Before any changes are made, it’s important to know who pays tax, who owns assets, and how much people have in their super for retirement.

Here's what should replace the $3 million super tax

With Div. 296 looming, is there a smarter way to tax superannuation? This proposes a fairer, income-linked alternative that respects compounding, ensures predictability, and avoids taxing unrealised capital gains. 

Chinese steel - building a Sydney Harbour Bridge every 10 minutes

China's steel production, equivalent to building one Sydney Harbour Bridge every 10 minutes, has driven Australia's economic growth. With China's slowdown, what does this mean for Australia's economy and investments?

9 winning investment strategies

There are many ways to invest in stocks, but some strategies are more effective than others. Here are nine tried and tested investment approaches - choosing one of these can improve your chances of reaching your financial goals.

Latest Updates

Retirement

The best way to get rich and retire early

This goes through the different options including shares, property and business ownership and declares a winner, as well as outlining the mindset needed to earn enough to never have to work again.

Shares

Boom, bubble or alarm?

After a stellar 2025 to date for equities, warning signs - from speculative froth to stretched valuations - suggest the market’s calm may be masking deeper fragilities. Strategic rebalancing feels increasingly timely.

Property

A perfect storm for housing affordability in Australia

Everyone has a theory as to why housing in Australia is so expensive. There are a lot of different factors at play, from skewed migration patterns to banking trends and housing's status as a national obsession.

Economy

Which generation had it toughest?

Each generation believes its economic challenges were uniquely tough - but what does the data say? A closer look reveals a more nuanced, complex story behind the generational hardship debate. 

Shares

Is the iPhone nearing its Blackberry moment?

Blackberry clung on to the superiority of keyboards at the beginning of the touchscreen era and paid the ultimate price. Could the rise of agentic AI and a new generation of hardware do something similar to Apple?

Fixed interest

Things may finally be turning for the bond market

The bond market is quietly regaining strength. As rate cuts loom and economic growth moderates, high-quality credit and global fixed income present renewed opportunities for investors seeking income and stability. 

Shares

The wisdom of buying absurdly expensive stocks (or not!)

Companies trading at over 10x revenue now account for over 20% of the MSCI World index, levels not seen since the dotcom bubble. Can these shares create lasting value, or are they destined to unravel?

Sponsors

Alliances

© 2025 Morningstar, Inc. All rights reserved.

Disclaimer
The data, research and opinions provided here are for information purposes; are not an offer to buy or sell a security; and are not warranted to be correct, complete or accurate. Morningstar, its affiliates, and third-party content providers are not responsible for any investment decisions, damages or losses resulting from, or related to, the data and analyses or their use. To the extent any content is general advice, it has been prepared for clients of Morningstar Australasia Pty Ltd (ABN: 95 090 665 544, AFSL: 240892), without reference to your financial objectives, situation or needs. For more information refer to our Financial Services Guide. You should consider the advice in light of these matters and if applicable, the relevant Product Disclosure Statement before making any decision to invest. Past performance does not necessarily indicate a financial product’s future performance. To obtain advice tailored to your situation, contact a professional financial adviser. Articles are current as at date of publication.
This website contains information and opinions provided by third parties. Inclusion of this information does not necessarily represent Morningstar’s positions, strategies or opinions and should not be considered an endorsement by Morningstar.