Why I’d buy shares and not overpay a mortgage

With ultra-low interest rates and a market crash, should you be buying shares or overpaying your mortgage? Let’s take a look.

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.

Interest rates, which were already low, have dropped further since the coronavirus outbreak. With stock markets also falling drastically, this has led people to question whether it is better to buy shares or to overpay their mortgage.

Ultimately, it comes down to compound interest.

Overpaying your mortgage

In March, the Bank of England cut the base rate to 0.1% to address the coronavirus crisis. High street banks often use the base rate as a reference point when setting their interest rates for savings accounts, loans, and mortgages.

For savers, money held in their savings accounts or Cash ISAs is likely earning them even less than it was before. For borrowers, this means that interest on loans will probably be lower.

Your mortgage payments might have dropped slightly in the past month. You be wondering whether you should just continue paying the same amount as before or do something else with the extra cash, like buying shares.

Small change

The cut in the base rate from 0.25% to 0.1% might seem minimal. However, over a long period, this could make a huge difference to a person’s wealth. Albert Einstein allegedly called compound interest the eighth wonder of the world: “He who understands it, earns it. He who doesn’t, pays it.”

Compound interest is literally when interest is earned on interest. The thinking goes that if you overpay your mortgage, you will be reducing the amount of the outstanding mortgage, which cuts the compound interest working against you.

When presented with this scenario, I like to flip it on its head. How can I get compound interest to work for me?

Buying shares

With the recent stock market crash, many shares in the FTSE 100 appear to be trading at a price below intrinsic value. In the past year, the index lost over 22%.

By comparison, at HSBC, a two-year fixed standard mortgage with a 90% maximum loan to value and maximum loan value of £400,000 currently attracts an initial interest rate of 1.79%, followed by a variable rate of 3.54%.

On the face of it then, overpaying your mortgage last year might have been better than buying shares, as the FTSE 100 lost money.

However, this does not show the whole picture.

Looking back over the past 30 years, a term of some mortgages, the FTSE 100 has returned roughly 150%. We can see then that investing in stocks and shares is a long-term game. The successful investor needs to be thinking about buying and holding for decades.

My fellow Fool, Rupert Hargreaves, notes that if you bought a FTSE 100 index fund during the financial crisis, you would have seen a return of roughly 9% per annum on your holdings to the start of March.

People who buy shares now will be hoping to benefit from the market’s likely recovery.

To me, the possibility for returns in what looks like an undervalued stock market far outweighs the benefit of paying off a mortgage at current interest rate levels.

I would rather have compound interest working for me, which is why I am buying shares.

T Sligo has no position in any of the shares mentioned. The Motley Fool UK has recommended HSBC Holdings. 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

Young Caucasian man making doubtful face at camera
Dividend Shares

Will the Diageo share price crash again in 2026?

The Diageo share price has crashed 35.6% over one year, making it one of the FTSE 100's worst performers in…

Read more »

Investing Articles

Is Alphabet still one of the best shares to buy heading into 2026?

The best time to buy shares is when other investors are seeing risks. Is that the case with Google’s parent…

Read more »

Investing Articles

Could the Barclays share price be the FTSE 100’s big winner in 2026?

With OpenAI and SpaceX considering listing on the stock market, could investment banking revenues push the Barclays share price higher…

Read more »

Investing Articles

Will the Nvidia share price crash in 2026? Here are the risks investors can’t ignore

Is Nvidia’s share price in danger in 2026? Stephen Wright outlines the risks – and why some might not be…

Read more »

Middle-aged white man pulling an aggrieved face while looking at a screen
Growth Shares

I asked ChatGPT how much £10,000 invested in Lloyds shares 5 years ago is worth today? But it wasn’t very helpful…

Although often impressive, artificial intelligence has its flaws. James Beard found this out when he used it to try and…

Read more »

Portrait of pensive bearded senior looking on screen of laptop sitting at table with coffee cup.
Investing Articles

Did ChatGPT give me the best FTSE stocks to buy 1 year ago?

ChatGPT can do lots of great stuff, but is it actually any good at identifying winning stocks from the FTSE…

Read more »

Surprised Black girl holding teddy bear toy on Christmas
Investing Articles

Who will be next year’s FTSE 100 Christmas cracker?

As we approach Christmas 2025, our writer identifies the FTSE 100’s star performer this year. But who will be number…

Read more »

Businessman with tablet, waiting at the train station platform
Investing Articles

I asked ChatGPT for an 8%-yielding passive income portfolio of dividend shares and it said…

Mark Hartley tested artificial intelligence to see if it understood how to build an income portfolio from dividend shares. He…

Read more »