How to Choose a Global ETF: Key Criteria

On understanding how to choose a global ETF, the key is focusing on the criteria that actually affect long-term results.

Global ETFs or funds that cover a big portion of the stocks around the world are popular because people view them as having a slice of the world economy.

In other words, if the world economy grows, investors in a global fund get some of the benefit of that.

That certainly appeals to me, and it’s one of the reasons I decided to go for a global fund rather than an S&P 500.

But how to choose a Global ETF?

And which ETF did I choose?

If you’re new here, you might be thinking, “This is a dividend website, why index funds?”

Those who’ve been around a while will know I organise my stock investments into what I call The Metronome Portfolio.

The Metronome Portfolio

It categorises investments into 3 sections;

• The base (dividends and income)
• The middle (index funds) 
• The tip (which covers the riskier investments)

I believe that the middle of this portfolio should be as set and forget as possible, essentially a “no-mind” aspect of your portfolio, and for that reason, I only want one fund in there, and I opt for a global Fund.

I chose FWRG to do that job.

Investing in a global ETF for your portfolio requires careful consideration of multiple factors to ensure you achieve the best possible long-term returns. 

Let me explain my key selection criteria and why the Invesco FTSE All-World UCITS ETF Acc (FWRG) stands out as a strong candidate for investors who have similar logic.

How to Choose a Global ETF

1. Geographical Coverage

Diversification is a fundamental principle of investing, helping to reduce risk by spreading exposure across different regions. 

A true global ETF should cover both developed and emerging markets to capture broad economic growth while mitigating localised downturns.

Comparison of Global Indexes

The FTSE All-World Index, in this case tracked by FWRG, includes a wide range of large and mid-cap stocks from approximately 50 countries. 

This means investors gain exposure to high-growth markets like China, India, and Brazil, which might be excluded in other ETFs focusing solely on developed economies.

Emerging markets often experience higher growth rates than developed ones. 

By investing in FWRG, you tap into future growth drivers, ensuring your retirement investments benefit from global economic expansion.

A Balanced Approach is Best

Now you might be thinking, if emerging markets are higher growth, so why bother with the rest of the global fund?

Rather than going all-in on emerging markets, I believe a global ETF like FWRG offers the best of both worlds:

• Exposure to emerging market growth (India, China, Brazil)
• Stability from developed markets (U.S., Europe, Japan)
• Lower volatility and better risk-adjusted returns over time

Going all-in on emerging markets might seem appealing due to their historically higher growth rates, but I think a balanced global approach is more sensible for long-term investing.

Emerging markets tend to be;

• More volatile
• Prone to political instability
• Prone to currency fluctuations
• Prone to weaker financial oversight 

During downturns, they often fall harder and take longer to recover. 

For instance, the MSCI Emerging Markets Index dropped over 50% in the 2008 financial crisis, compared to a 40% decline in the MSCI World Index, and some countries, like Brazil and Russia, took more than a decade to recover.

Another problem with going all in on emerging markets is that they often face challenges like;

• Higher inflation
• Liquidity constraints
• Restricted capital movement in some regions

Developed economies like the U.S. and Europe still lead in innovation, corporate governance, and economic stability. 

The S&P 500 alone accounts for about 40% of global equity markets, reinforcing its influence.

So, by investing in a balanced global ETF, investors can capture emerging market growth while minimising excessive risks, aiming for long-term stability.

2. Total Expense Ratio (TER) When Choosing a Global ETF

TER represents the annual percentage cost of managing the ETF. 

It includes administrative fees, management costs, and operational expenses, reducing your net returns over time.

ETF Cost Comparison

With a TER of 0.15%, FWRG is one of the more affordable global ETFs, though the SPDR MSCI ACWI ETF (Ticker: ACWI) offers an even lower TER of 0.12%.

It actually lowered its fees after I had already chosen FWRG, and I decided to stick with FWRG rather than hopping between any fund that decides to lower its fees.

However, FWRG remains a strong contender due to its accumulating structure and broad market exposure, making it a cost-effective choice for long-term investors.

The Compounding Effect of Low Fees

Assuming a £50,000 investment over 20 years with an 8% annual return, here’s how TER impacts final portfolio value:

Assuming all else remains equal, lower costs increase your retirement savings, making FWRG a solid option here.

3. Dividend Policy: Accumulating vs. Distributing

ETFs can either:

• Distribute dividends (payouts in cash to investors), these will have (Dist) at the end of the name.
• Accumulate dividends (reinvest them within the fund), these will have (Acc) at the end of the name.

Invesco FTSE All-World UCITS ETF Acc (FWRG) has “Acc” in the name, so FWRG is an accumulating ETF, meaning dividends are automatically reinvested, increasing the share price and maximising long-term growth.

Accumulation works best for what I need because:

• No manual reinvestment required, so more aligned with the “no-mind” approach.
• Dividends compound over time
• More efficient for tax-free accounts like SIPP, etc.

If you are holding outside a tax-advantaged account, then it’s a bit more complicated.

4. Replication Method: Physical vs. Synthetic

ETFs replicate an index either physically or synthetically.

• Physical Replication: The ETF directly holds the underlying stocks
• Synthetic Replication: The ETF uses derivatives to mimic index performance

FWRG follows a sampling-based physical replication method, meaning it holds a representative selection of stocks rather than every single company in the FTSE All-World index.

Physical ETFs have greater transparency and lower counterparty risk, whereas Synthetic ETFs carry risks related to derivative contracts.

For what I am looking for, physical replication is generally preferable due to its reliability and lower risk profile. There is no need to increase obscure risks for relatively little benefit.

5. Fund Size & Liquidity

A larger fund typically has:

• Lower bid-offer spreads
• Greater liquidity (easier to buy/sell shares)
• Higher investor confidence

FWRG has an AUM of approximately £764 million, which provides reasonable liquidity and stability, though larger ETFs may offer even narrower bid-offer spreads.

The largest fund is likely VWRL by Vanguard, but the difference in liquidity or bid-offer spreads is probably negligible. 

6. Domicile & Tax Efficiency

The country where an ETF is domiciled affects taxation, particularly withholding tax on dividends from U.S. stocks. 

A tax-efficient domicile ensures that investors retain more of their returns.

Here’s how Ireland and Luxembourg compare as domiciles for ETFs.

1. Ireland-domiciled ETFs benefit from a 15% U.S. withholding tax rate due to the U.S.-Ireland tax treaty. This ultimately means investors keep a larger portion of dividends from U.S. stocks.
2. Luxembourg-domiciled ETFs, however, are typically subject to a 30% U.S. withholding tax, as Luxembourg lacks a favourable tax treaty with the U.S. Some Luxembourg ETFs use more complicated tax-efficient structures, but Ireland remains the preferred domicile for tax efficiency.

This matters because FWRG is domiciled in Ireland, meaning it benefits from the lower 15% U.S. withholding tax, making it more tax-efficient for holding U.S. stocks within a global portfolio.

 Over time, these tax savings can significantly improve net returns, especially for long-term investors.

7. Currency Exposure

FWRG trades in GBP, eliminating foreign exchange (FX) fees when buying through UK platforms.

That being said, underlying assets are priced in multiple currencies, so currency fluctuations will still affect performance. 

Even though you buy and sell the ETF in GBP, its underlying holdings are in various global currencies such as USD, EUR, and JPY. 

This means that if the GBP strengthens against these currencies, the value of those foreign holdings decreases when converted back to GBP, reducing the ETF’s performance.

Similarly, if the GBP weakens, the value of foreign holdings increases, boosting returns. 

So you should be aware that while trading in GBP avoids direct FX transaction costs on the platform, currency movements still play a role in long-term returns.

Final Thoughts on How to Choose a Global ETF

With broad global exposure, low costs, tax efficiency, and a structure optimised for long-term growth, FWRG is my top choice for an ETF. 

While other ETFs may have slightly lower fees, FWRG offers an excellent balance of cost, diversification, and efficiency, making it an ideal investment for long-term retirement savings.

Going straight to the lowest costs (TER) as a strict rule means that you will always have to keep up to date with the current fee structures, which takes away from the intention of it being “no-mind”, in my opinion.

I am happy with FWRG as the choice for the “middle of the metronome” section of my portfolio and don’t feel the need to change it.

So those are the criteria on how to choose a Global ETF and why I chose FWRG.