You can start building a low-cost ETF portfolio with £100. The key is to use tools that make small investments practical: fractional investing, a suitable account type, diversified ETFs, low costs and, if it suits your circumstances, regular contributions over time.
This guide explains how to approach a first ETF portfolio from £100, what to think about before choosing investments, and how InvestEngine can help UK investors build DIY ETF portfolios in a low-cost way.
Capital at risk. The value of your investments can go down as well as up, and you may get back less than you invest. This article is for general information only and is not personal advice.
How to build an ETF portfolio from £100: the basics
| Step | What to do |
|---|---|
| 1 | Choose an investment account |
| 2 | Decide your goal and timeframe |
| 3 | Use fractional investing to spread £100 across ETFs |
| 4 | Keep platform and ETF costs low |
| 5 | Consider regular investing to build over time |
A £100 portfolio will not be perfect from day one, and it does not need to be. For many new investors, the first goal is simply to start in a controlled, low-cost way, understand how investing feels, and build habits that can be continued over time.
The important point is that a small starting amount should still be treated seriously. Investors should understand what they are buying, how much risk they are taking, and whether the investment fits their timeframe.
What is an ETF?
An ETF, or exchange-traded fund, is an investment fund that can be bought and sold on a stock exchange. Many ETFs are designed to track an index, such as the S&P 500, FTSE All-World or FTSE 100.
Instead of buying individual shares one by one, an ETF can give investors exposure to a basket of investments through a single fund. Depending on the ETF, that basket might include hundreds or thousands of companies, government bonds, corporate bonds, commodities or a specific market theme.
This is one reason ETFs are often used by beginner investors. They can make it easier to build diversified exposure without needing to research and select individual companies. However, ETFs still carry investment risk. If the market or assets inside the ETF fall in value, the ETF can fall too.
Can you start investing with £100?
Yes. A £100 starting amount can be enough to begin investing, particularly where fractional investing is available.
Fractional investing means investors can buy part of an ETF rather than needing to buy a full ETF unit. This matters because some ETFs can have a high unit price. Without fractional investing, a small portfolio might only be able to buy one fund, or might leave part of the money sitting uninvested. With fractional investing, investors can spread a smaller amount across several ETFs if they choose to.
Starting with £100 can also help new investors build confidence. It gives them a way to learn how markets move, how their account works and how they feel when investments rise or fall. That learning can be valuable before committing larger sums.
However, starting small does not remove risk. A £100 ETF portfolio can still fall in value, and investors should only invest money they are prepared to leave invested for the long term.
Step 1: choose your account type
Before choosing ETFs, it helps to choose the right account. The account determines how the investment is held, how tax may apply, and when the money can be accessed.
| Account | May suit investors who want |
|---|---|
| Stocks and Shares ISA | Tax-efficient investing with flexibility |
| SIPP | Long-term retirement investing |
| General Investment Account | Flexible investing outside ISA or pension limits |
| Business Account | A way to invest surplus company cash |
A Stocks and Shares ISA is often used by investors who want tax-efficient investing with access before retirement. A SIPP is designed for retirement and can offer pension tax benefits, but money is usually locked away until the minimum pension age. A General Investment Account can be useful where ISA or pension allowances are not suitable or have already been used.
There is no single right account for everyone. The right choice depends on your goal, timeframe, tax position and whether you may need access to the money. Tax treatment depends on personal circumstances and may change in future.
Step 2: decide your approach
Once the account is chosen, the next step is to decide what the portfolio is trying to do. A DIY ETF portfolio gives investors control over the ETFs they hold and the proportion invested in each one.
For a new investor, this usually starts with a few simple questions. Is the money being invested for five years, 10 years or longer? Is the aim long-term growth, income, capital preservation or a mix? How comfortable would the investor be if the portfolio fell by 10%, 20% or more during a difficult market?
These questions matter because the right portfolio for a cautious investor may look very different from the right portfolio for someone investing for several decades. A portfolio focused mainly on equities may offer higher long-term growth potential, but it can also be more volatile. Adding bonds or other assets may reduce volatility, although it can also change the expected return.
The aim is not to predict markets perfectly. It is to build a portfolio that the investor can understand and stick with through normal market ups and downs.
Step 3: diversify with ETFs
Diversification means spreading money across different investments so the portfolio is not overly reliant on one company, sector, country or asset class.
This is one of the main reasons investors use ETFs. A single global equity ETF, for example, may hold shares in companies across many countries and sectors. Other ETFs can add exposure to specific areas, such as UK equities, bonds, commodities or long-term themes.
A £100 ETF portfolio could include exposure to:
- Global equities: broad company exposure across countries
- UK equities: UK-listed companies
- Bonds: government or corporate bond exposure
- Commodities: assets such as gold
- Thematic ETFs: specific sectors or long-term themes
This is not a suggested portfolio or personal recommendation. The right mix depends on personal goals, timeframe and risk appetite. Some investors may prefer one broad global ETF as a simple starting point. Others may want to combine different ETFs to create a more tailored portfolio.
The key is to understand what each ETF adds. If two ETFs hold many of the same companies, the portfolio may be less diversified than it first appears. Similarly, adding a focused ETF can increase concentration risk even if the portfolio has more holdings on paper.
Step 4: keep costs low
Costs matter because they reduce the return investors keep. This is especially important for long-term investors, where small differences in fees can compound over many years.
There are several costs to consider. Platform fees are charged by some investment platforms for holding investments. Dealing fees may apply when buying or selling. ETFs also have their own ongoing charges, which are taken from the fund rather than usually appearing as a separate bill. Bid-offer spreads and currency conversion costs can also affect returns.
With InvestEngine, DIY investors pay 0% dealing fees and 0% platform fee on DIY portfolios. ETF costs apply.
Low costs should not be the only factor when choosing an ETF, but they are an important part of long-term investing. Investors should also look at the index, asset class, diversification, fund size, replication method and whether the ETF fits the rest of the portfolio.
Step 5: consider regular investing
A £100 starting portfolio can be useful, but regular contributions are often what help a portfolio build over time.
Regular investing means adding money weekly, monthly or at another chosen interval. This can help investors build discipline and reduce the pressure of trying to choose the perfect moment to invest. It can also support pound-cost averaging, where money is invested gradually rather than all at once.
InvestEngine offers tools that can help investors automate this process, including Savings Plans, AutoInvest, one-click rebalancing and fractional investing. These tools are designed to help investors keep a DIY portfolio aligned with their chosen allocations.
Automation does not guarantee returns, and it does not remove risk. But it can make it easier to stick with a plan, particularly for investors who want to build gradually rather than manage every contribution manually.
Example ways investors think about a £100 ETF portfolio
A £100 portfolio can be approached in different ways, depending on the investor’s goal and risk tolerance.
Some investors may prefer a simple global approach, using one broad global equity ETF as a starting point. Others may want to combine global equities with UK equities or bonds. Some may include a small allocation to commodities such as gold, although commodity exposure comes with its own risks and may not suit everyone.
The important thing is that each ETF should have a clear role. A portfolio does not become stronger simply because it contains more funds. It becomes stronger when the holdings work together and match the investor’s goals.
For beginners, simplicity can be valuable. A smaller number of well-understood ETFs may be easier to manage than a more complicated portfolio with overlapping holdings.
Risks of building an ETF portfolio
ETF portfolios can be simple and low cost, but they still carry risk.
- Market risk: ETF values can fall, and investors may get back less than they invest.
- Concentration risk: focused ETFs can be more volatile than broad market ETFs.
- Currency risk: overseas ETFs can be affected by exchange rate movements.
- ETF cost risk: ongoing charges and other costs reduce returns over time.
- Behavioural risk: reacting to short-term volatility can affect long-term outcomes.
- Tax risk: tax rules can change, and tax treatment depends on personal circumstances.
Diversification can help manage risk, but it cannot remove it completely. Investors should be comfortable with the possibility that their portfolio may fall in value, especially over shorter periods.
How to build a low-cost ETF portfolio with InvestEngine
InvestEngine is a UK-based ETF investing platform, authorised and regulated by the Financial Conduct Authority, built for long-term investors who want to create DIY ETF portfolios.
With InvestEngine, you can buy and sell ETFs with 0% dealing fees and 0% platform fee on DIY portfolios. ETF costs apply.
To get started, investors can create an account, choose an ISA, SIPP, GIA or Business Account, search for the ETFs they want and decide how much to invest. Fractional investing can make it possible to invest smaller amounts across more than one ETF, while Savings Plans can help build the portfolio over time.
The same principles still apply: choose an account that fits the goal, understand the ETFs, keep costs low and make sure the portfolio matches the investor’s risk appetite and timeframe.
FAQs
Can I start investing in ETFs with £100?
Yes. Fractional investing can make it possible to split £100 across more than one ETF, rather than needing to buy a full ETF unit. The value of those ETFs can still fall as well as rise.
What is the cheapest way to invest in ETFs?
A low-cost approach usually means using a platform with low or no dealing/platform fees and choosing ETFs with low ongoing charges. Investors should also consider the ETF’s exposure, risk and fit within the wider portfolio.
Are ETFs risky?
Yes. ETFs are investments, so they can fall in value. The level of risk depends on what the ETF holds. A broad global equity ETF will usually behave differently from a focused sector ETF, bond ETF or commodity ETF.
What is fractional investing?
Fractional investing lets investors buy part of an ETF rather than a full unit. This can make it easier to start with smaller amounts and spread money across multiple ETFs.
Is one ETF enough for a beginner portfolio?
It can be, depending on the ETF and the investor’s goal. A broad global ETF may already hold many companies across countries and sectors. However, some investors may want to add other ETFs for different asset classes or exposures.
Does InvestEngine charge dealing fees?
InvestEngine charges 0% dealing fees for buying and selling ETFs. DIY portfolios also have 0% platform fees. ETF costs apply.
In summary
A £100 ETF portfolio can be a practical starting point for long-term investing. Fractional investing can make small amounts easier to invest, while ETFs can help investors access diversified markets through a small number of funds.
The main things to focus on are the account type, investment goal, timeframe, diversification, costs and risk. A portfolio does not need to be complicated to be useful, but it should be understandable and suitable for the investor’s circumstances.
Capital at risk. ETF costs apply. Tax treatment depends on your personal circumstances and may change in future. This communication is for general information only and does not constitute personal advice.