Would investing £100 a month in the FTSE 100 beat buying Premium Bonds?

Billions have been invested in Premium Bonds. Investing in stocks and shares is more likely to make someone rich.

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.

Premium Bonds, which are issued by National Savings & Investments (NS&I), cost £1 each. They do not pay any interest. Instead, each eligible bond is entered into a monthly draw for prizes ranging from £25 to £1m. However, the odds of any bond winning a prize are 24,500 to 1. Given the fact that Brits have invested over £84bn in Premium Bonds, those odds do not appear to matter to them.

It is true that the more bonds a person owns, the higher the chance of a prize. Also, the UK Treasury backs any savings and prizes won, so an investor will never get back less than they put in. Additionally, Premium Bond prizes are entirely tax-free. But what kind of returns can an investor in Premium Bonds expect?

Tried and tested

Let’s look at how a £100 per month Premium bond investment, over 25 years, is likely to perform. First, we need probabilities of winning each of the monthly prizes available, and the chance of winning nothing. The required data for calculating these is available on the prize draw details section of the NS&I website.

We will start with 100 bonds that go into the monthly draw. Any prizes won will be used to buy more bonds, and another 100 bonds are purchased each month. There is a limit of 50,000 eligible bonds – anything over this amount is ineligible for the prize draws, and we will do the same in our study.

Ten thousand trials of this experiment are enough to generate some expectations. On average, the wealth level at the end of 25 years was £36,040. 10% of the trials generated a wealth level of £36,625 or higher. 1% of trials resulted in netting £40,950 or more. The truly lucky, the 0.1% club, could expect their investment to grow to £91,825 or more, with one (0.01% of trials) sitting on £1,036,150.

99% of the time, investing £100 per month for 25 years in Premium Bonds will generate £40,950 or less. An investor can do better than this is they find an investment that returns 2.43% each year on average.

Premium returns

The good news is that there are investments out there that have long-term average returns that beat 2.43%. The FTSE 100, with dividend reinvestment, had an average return of 6.4% over the last 25 years. Investing in the FTSE 100 with a low-cost tracker fund, held inside an ISA, would mean most of that return accrued to the investor.

There are individual stocks like Unilever and RELX that have delivered 10-year average returns of 11.58% and 16.89% respectively. Both of these are fancied by Nick Train, a fund manager with exemplary performance, and are considered sustainable dividend payers. Both of these stocks can be held inside an ISA, as could other suitable picks.

Of course, there are risks with stock market investing, and more so with investing in individual stocks. You could get back less than you put in, which is not the case with Premium Bonds. However, I don’t believe it is controversial to say you are more likely to end up with more wealth if you invest for the long term in the stock market inside an ISA, compared to investing in Premium Bonds.

James J. McCombie owns shares in Unilever. The Motley Fool UK owns shares of and has recommended Unilever. The Motley Fool UK has recommended RELX. 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

British flag, Big Ben, Houses of Parliament and British flag composition
Investing Articles

My 3 FTSE 100 predictions for 2026

Ben McPoland sees another positive year for the FTSE 100 index, including a return to form for one very disappointing…

Read more »

Two business people sitting at cafe working on new project using laptop. Young businesswoman taking notes and businessman working on laptop computer.
Dividend Shares

Building powerful passive income from just £20 a week!

Starting off with just a few quid a week, one can build potent passive income over time. I've already done…

Read more »

Group of young friends toasting each other with beers in a pub
Investing Articles

FTSE 100 shares: has a once-a-decade chance to build wealth ended?

The FTSE 100 index has had a strong 2025. But that doesn't mean there might not still be some bargain…

Read more »

Passive income text with pin graph chart on business table
Investing Articles

I asked ChatGPT for its top passive income ideas for 2026 and it said…

Stephen Wright is looking for passive income ideas for 2026. But can asking artificial intelligence for insights offer anything valuable?

Read more »

Woman riding her old fashioned bicycle along the Beach Esplanade at Aberdeen, Scotland.
Investing Articles

Here’s how a 10-share SIPP could combine both growth and income opportunities!

Juggling the prospects of growth and dividend income within one SIPP can take some effort. Our writer shares his thoughts…

Read more »

Tabletop model of a bear sat on desk in front of monitors showing stock charts
Investing Articles

The stock market might crash in 2026. Here’s why I’m not worried

When Michael Burry forecasts a crash, the stock market takes notice. But do long-term investors actually need to worry about…

Read more »

Person holding magnifying glass over important document, reading the small print
Investing Articles

Is this FTSE 250 retailer set for a dramatic recovery in 2026?

FTSE 250 retailer WH Smith is moving on from the accounting issues that have weighed on it in 2025. But…

Read more »

Young Black woman using a debit card at an ATM to withdraw money
Investing Articles

I’m racing to buy dirt cheap income stocks before it’s too late

Income stocks are set to have a terrific year in 2026 with multiple tailwinds supporting dividend growth. Here's what Zaven…

Read more »