Investment theories which go against conventional wisdom

There are a few investment theories which go against conventional wisdom. You may have heard the old stock market maxim; ‘Sell in May and go away.’ It ended with, ‘Don’t come back until St. Leger day’. The meaning and advice of this saying was to sell up in May and enjoy the English summer season.

Unfortunately, Wall Street and the Shanghai Composite Index don’t take head of the English season, and the old saying has dropped out of favour!

But, are there any other seemingly outdated investment theories and should you pay any attention to them?

The greater fool

Next we look at the ‘Greater Fool Theory’. This proverb simply says it doesn’t matter what you pay for an investment. But, you need to find a ‘greater fool’ to buy it at a higher price. Fortunately, the FCA do not recognise ‘greater fool’ as satisfying the requirement of ‘know your client…’.

‘Buy the worst performing market.’ Has one of the world’s stock markets performed poorly this year? Then believers of this theory say you should invest in it next year. 2019 was generally a good year for world stock markets. However, South Korea lagged behind, only rising 9%. The Brazilian market, in contrast, rose by 32%.

What happened in 2020? South Korea was up by 31%, Brazil by just 3%. And anyone following this theory will be heavily invested in the UK’s FTSE index in 2021 – compared to other countries, the UK’s leading index performed poorly in 2020.

Prospect theory

The ‘Prospect Theory’ tells us that investors are more worried about the prospect of loss than they are attracted by the expectation of profit. If a portfolio grows at a steady 5% for three years it will – allowing for compound interest – have the same return as one which grows 12%, falls 2.5% and then grows by 6%.

The theory tells us the majority of investors will opt for the steady 5% return and, in many ways, this theory goes right to the heart of what a good financial adviser does. It is not about the latest fashionable investment theory or the return of an old favourite, it is about knowing your client, working with your client over the long term and building a savings and investment portfolio that matches the client’s level of risk and financial goals. Theories may come and go and that is a fundamental which will never change.

Other blogs and guides:

Can you become a millionaire by investing in one company?

Can money really buy you happiness?

A guide to wealth preservation and wealth transfer

Guide to securing your financial future

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