My plan to turn £100 a week into £1m

Rupert Hargreaves explains how he’s planning to make a fortune in the stock market with just a £100 investment per week.

The content of this article was relevant at the time of publishing. Circumstances change continuously and caution should therefore be exercised when relying upon any content contained within this article.

You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn More.

You don’t need to be a maths whizz or well connected City stockbroker to be a good investor. Indeed, today anyone can open up an online share dealing account with a small deposit. Most online stock brokers also offer regular investment plans, starting from as little as £50 a month.

Therefore, if you can make the most of these offers, it’s relatively straightforward to make a million in the market. All you need to do is set up a regular contribution plan, sit back, and relax.

The best index

The best way to invest your money with a regular contribution plan is to buy a low-cost passive tracker fund. The great thing is they don’t require any babysitting or additional work on your part.

Passive tracker funds only replicate their underlying stock indexes. As a result, all you need to do is pick one or two, and that’s really it. You don’t need to monitor these funds to make sure their managers aren’t straying into inappropriate investments. 

For UK investors, the two best indexes to track are the FTSE 100 and FTSE 250. Since inception, the FTSE 100 has produced an average annual return for investors of around 9%. Meanwhile, the FTSE 250 has returned approximately 12%. So it seems that if you’re looking to get the most bang for your buck, the FTSE 250 is the best index to track.

Low-cost

The best low-cost FTSE 250 tracker fund on the market at the moment charges just 0.10% per annum in management fees. This excludes stockbroker platform costs. These fees could add 0.40% per annum on top, although some providers charge much less.

Keeping costs low is vital if you want to get the most out of your money. For example, an investment of £100 a month in the FTSE 250 would be worth £1m after 39 years. That’s assuming an average annual rate of return of 12%, and excludes costs and charges. 

However, if you end up paying 2% per annum in fees, your nest egg would be worth just £507,000 after 39 years. Keeping total costs below 0.5% would allow you to hit the £1m benchmark in 41 years. 

Slow and steady

It’s relatively straightforward to make £1m in the stock market if you stick to a regular investing plan and keep costs low. The FTSE 250 is an excellent index to track for this purpose because it offers exposure to some of the UK’s fastest-growing companies.

Many of its constituents also have an international presence. This should give investors some diversification away from Brexit uncertainty.

The most important thing to remember is that becoming a millionaire won’t happen overnight. It takes time and patience. But as the figures above show, as long as you can meet the monthly contribution target and let the market take care of the rest, making a million with the FTSE 250 isn’t impossible.

Rupert Hargreaves owns no share mentioned. The Motley Fool UK has no position in any of the shares mentioned. Views expressed on the companies mentioned in this article are those of the writer and therefore may differ from the official recommendations we make in our subscription services such as Share Advisor, Hidden Winners and Pro. Here at The Motley Fool we believe that considering a diverse range of insights makes us better investors.

More on Investing Articles

ISA coins
Investing Articles

The ISA deadline’s almost on us! Here’s a last-minute FTSE 100 share to consider

Investors have just a month to max out their Stocks and Shares ISA allowance for the 2026 tax year. Here…

Read more »

Young Caucasian man making doubtful face at camera
Dividend Shares

Down 24% in 10 months, Greggs shares are baking bad!

After a turbulent 2025, Greggs shares continue to bounce around this year. But with the stock trading at levels seen…

Read more »

Asian man looking concerned while studying paperwork at his desk in an office
Investing Articles

A stock market crash feels like it might be imminent

Conflict in the Middle East means a stock market crash feels like a real possibility right now. But being ready…

Read more »

Rolls-Royce's Pearl 10X engine series
Investing Articles

Should I buy Rolls-Royce shares as they march ever higher?

Rolls-Royce is making billions of pounds a year and looks set to do even better in future -- so what's…

Read more »

Smiling family of four enjoying breakfast at sunrise while camping
Investing Articles

£1,000 buys 110 shares in this UK beverage stock that’s smashing Diageo 

Shares of Tanqueray-maker Diageo are languishing at multi-year lows. So why is the stock behind this tonic water brand on…

Read more »

UK financial background: share prices and stock graph overlaid on an image of the Union Jack
Investing Articles

What next for Aviva shares after a cracking set of 2025 results?

Aviva achieving its 2026 financial goals a year ahead of schedule has got to be good for the shares... oh,…

Read more »

This way, That way, The other way - pointing in different directions
Investing Articles

Should I buy stocks or look to conserve cash right now?

In a market dealing with AI uncertainty and conflict in the Middle East, should investors be looking for stocks to…

Read more »

Investing Articles

Here’s how many British American Tobacco shares it takes to earn a £1,000 monthly second income

Is an AI-resistant business with a 5.38% dividend yield a good choice for investors looking for a second income in…

Read more »