ASX ETF Overlap Trap: Build Smarter Diversified Portfolios

Highlights

• Hidden overlap can weaken diversification

• Similar ETFs may mirror the same holdings

• Smart allocation improves portfolio efficiency

ETF investing can appear diversified at first glance, but overlapping holdings often reduce effectiveness. A focused and intentional allocation strategy helps improve diversification, reduce costs, and simplify portfolio management.

The rise of Exchange Traded Funds has transformed how investors approach markets, especially when tracking benchmarks like the ASX 200. While ETFs are often seen as a simple route to diversification, many portfolios today carry hidden overlap, limiting the true benefits of diversification and efficiency.

Much like a balanced fitness routine requires varied exercises, investing also demands thoughtful allocation. Relying heavily on similar ETFs can create repetition rather than diversification, leading to unnecessary complexity and costs.

Understanding the Illusion of Diversification

At first glance, holding multiple ETFs may seem like a well-diversified approach. However, many funds track similar indices or sectors, resulting in repeated exposure to the same companies.

For example, broad-market ETFs that follow large-cap Australian indices often share a significant portion of their holdings. This means adding more ETFs does not necessarily expand diversification but instead increases duplication.

This overlap creates an illusion of diversification while concentrating exposure in the same underlying assets.

ASX Index Overlap: A Closer Look

A common example of ETF overlap can be observed between funds tracking the ASX 200 and the ASX 300.

Consider the following ETFs:

• Betashares Australia 200 ETF (ASX:A200)

• Vanguard Australian Shares Index ETF (ASX:VAS)

While these funds track different indices, their portfolios are largely similar due to market capitalisation weighting. Larger companies dominate both indices, meaning the majority of holdings overlap.

Core Holdings Similarity

The largest companies in the Australian market tend to dominate both indices. These companies form the backbone of both ETFs, resulting in highly similar exposure at the top end.

Mid-Segment Overlap

Companies beyond the largest group still contribute significantly to both indices. This segment further increases the similarity between the ETFs.

Limited Additional Exposure

The additional companies included in broader indices like the ASX 300 contribute only marginal diversification. Their smaller size results in minimal impact on overall portfolio composition.

In practical terms, much of the exposure gained through one ETF is already present in the other.

Similar ETFs in the Market

Other ETFs offering comparable exposure include:

• iShares S&P/ASX 200 ETF (ASX:IOZ)

• SPDR S&P/ASX 200 ETF (ASX:STW)

• Global X Australia 300 ETF (ASX:300)

These funds follow similar strategies, reinforcing the importance of evaluating whether multiple ETFs are truly adding value or simply repeating exposure.

The Hidden Costs of Overlapping ETFs

Direct Financial Impact

Holding multiple ETFs with similar holdings can increase overall costs.

• Brokerage Costs: Each transaction adds fees, especially when investing regularly across several funds

• Management Fees: Even low fees can accumulate when spread across multiple overlapping ETFs

Administrative Complexity

Managing several ETFs increases the workload involved in maintaining a portfolio.

• Tracking multiple holdings and cost bases

• Managing additional tax reporting

• Handling more documentation and statements

Decision-Making Challenges

A larger number of similar holdings can complicate investment decisions.

During market volatility, managing multiple overlapping ETFs can slow down responses and create confusion about allocation adjustments.

When Overlap Can Be Strategic

Despite its drawbacks, overlap is not always negative. In certain cases, it can serve a clear purpose.

Separating Investment Strategies

Investors sometimes use similar ETFs to separate long-term investments from shorter-term strategies. This allows for clearer tracking and management of different objectives.

Managing Tax Considerations

Switching between ETFs may trigger tax events. In such cases, maintaining existing holdings while gradually adjusting exposure can be a practical approach.

Building a Smarter Portfolio

Instead of stacking similar ETFs, a more effective strategy is to combine complementary exposures.

Combining Growth and Income

For example:

• Betashares Australia 200 ETF (ASX:A200) offers broad market exposure

• Betashares S&P Australian Shares High Yield ETF (ASX:HYLD) focuses on income generation

While some overlap exists, their objectives differ significantly, creating a balanced approach.

Adding Sector-Specific Exposure

Introducing sector-focused ETFs can enhance diversification further.

• Betashares S&P/ASX Australian Technology ETF (ASX:ATEC) provides targeted exposure to the technology sector

This approach adds variety without excessive duplication, helping to create a more dynamic portfolio.

Enhancing Diversification Beyond Core Holdings

True diversification comes from combining different types of exposures rather than repeating the same ones.

Investors can explore:

• Sector-specific ETFs

• Global equity funds

• Income-focused strategies like ASX dividend stocks

• Broader indices such as the ASX 100

By spreading investments across different segments, portfolios can achieve better balance and resilience.

Auditing Your Portfolio for Overlap

Evaluating ETF overlap is an important step in improving portfolio efficiency.

Practical Steps

• Review ETF holdings available from fund providers

• Compare top holdings across funds

• Identify repeated exposures

Using Tools and Technology

Portfolio comparison tools and data analysis methods can help uncover overlap. Reviewing holdings data can provide insights into duplication and concentration risks.

Regular portfolio reviews ensure that diversification remains intentional rather than accidental.

The Role of Intentional Diversification

Diversification is not just about the number of holdings but about how those holdings interact.

A well-structured portfolio should:

• Avoid unnecessary duplication

• Maintain clarity in investment objectives

• Balance growth, income, and sector exposure

Intentional diversification allows each component of a portfolio to serve a distinct role.

ETF investing remains a powerful strategy for accessing markets efficiently. However, the growing number of available funds has made it easier to unintentionally create overlapping portfolios.

By focusing on complementary exposures, managing costs, and regularly reviewing holdings, investors can build portfolios that are both diversified and efficient.

The key lies in understanding that more ETFs do not always mean better diversification. Thoughtful allocation and clear strategy make the real difference.