Investing in banks? Here’s what I think you need to know

Thinking about investing in the banking sector? Read this guide to help you get started.

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.

Some of the biggest companies in the UK are banks, and so most investors at some point in their careers will consider the financial sector as a place to deploy capital. However, although banks resemble other businesses in some respects, they do differ from sectors like retail or technology in material ways. Here’s what I think you need to know to get started.

Fundamental events

There are a number of macro variables that can dictate how successful a bank is. First there are interest rates. It should be no surprise to anyone that most banks make their money by providing loans to borrowers. The higher the national rate, the more money banks make. This makes them somewhat unlike other stocks, which tend to dislike higher interest rates (as the cost of borrowing for businesses goes up). 

Another important fundamental factor to consider is banking regulation. For instance, the Thatcher-era ‘Big Bang’ deregulation of the sector had a profoundly transformative impact on banks, allowing the City of London to become one of, if not the most, powerful financial centres in the world. Similarly, it is widely believed that a Jeremy Corbyn-led Labour government would be hostile to banks, and would introduce extensive legislation to rein them in, leading to a sell-off of financial stocks.

Valuation techniques

When investing in a bank, there are essentially two factors you want to consider. Firstly, is your target efficient at making money? Secondly, is it well-insulated against adverse events? So in other words, what is the return, and what is the risk? Here are two metrics that you should use when analysing financial institutions.

Net interest margin (NIM). This is (arguably) the most important bank metric there is. It is simply the difference between the interest that banks charge on loans and the interest that they pay out to creditors. There are two main ways that banks can grow their NIM — loan growth (getting more customers to take out higher-rate loans) and deposit growth (getting more customers to deposit their money at lower rates). Banks like it when customers take out more loans than they deposit. As an investor, what you want is to see a steadily growing NIM. However, you should be wary of banks that are offering loans to customers with poor credit — sooner or later that will come back to haunt them. 

Non-performing loan ratio. This is a measure of a bank’s risk. A non-performing loan is a loan in default. Naturally, banks should want to minimise their exposure to bad creditors, but sometimes they do not. This can be either a result of deliberate mismanagement, or an inability to accurately quantify risk. Many financial institutions fell into the latter trap in the run-up to the financial crisis by exposing themselves to mortgages that they believed were low-risk, but in truth were high-risk. The ratio is simply the number of bad loans as a percentage of total loans. Healthy banks really should not have a ratio of more than 2%. 

Neither Stepan nor The Motley Fool UK have a 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

Santa Clara offices of NVIDIA
Investing Articles

£5,000 invested in Nvidia stock 6 months ago is now worth…

Nvidia stock's taking a breather at the moment. But it could be getting ready for its next move higher, says…

Read more »

British coins and bank notes scattered on a surface
Investing Articles

I hold Lloyds. Is it madness to buy Barclays shares too?

Harvey Jones is keen to buy Barclays shares but wonders whether he's simply doubling down, given that he already holds…

Read more »

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

It’s time we all took a long, cold look at the Lloyds share price

The Lloyds share price has been good to Harvey Jones, making him a huge fan of the FTSE 100 bank.…

Read more »

Warren Buffett at a Berkshire Hathaway AGM
Investing Articles

Warren Buffett didn’t retire early. But could his investing wisdom help you do so?

Warren Buffett's wisdom from decades of stock market investing is actionable even for a modest investor who simply aims to…

Read more »

Young female hand showing five fingers.
Investing Articles

5 compelling investment ideas for a Stocks and Shares ISA in 2026

Edward Sheldon discusses some ideas to consider for a Stocks and Shares ISA and highlights a UK stock that could…

Read more »

Man writing 'now' having crossed out 'later', 'tomorrow' and 'next week'
Investing Articles

Is this the best time to buy shares in a long time?

Earlier this week, Bill Ackman stated on X that this is the best time to buy shares in a long…

Read more »

A senior man and his wife holding hands walking up a hill on a footpath looking away from the camera at the view. The fishing village of Polperro is behind them.
Investing Articles

£1,000 buys 35 shares in an incredibly reliable FTSE 100 dividend stock

Despite falling 72% from their highs, shares in this FTSE 100 company have been an incredibly reliable source of dividend…

Read more »

Warren Buffett at a Berkshire Hathaway AGM
Investing Articles

This is what Warren Buffett has to say about passive income — and I’m listening!

While searching for new ways to earn passive income, our writer takes to heart sage advice from the Oracle of…

Read more »