The FTSE 100 index continued its slide last week, taking it to almost 16% below levels a decade ago. Investors could be forgiven for questioning the value of holding equities, despite advisers recommending the stock market for five years or more.

Here we consider 20 reasons to stick with shares:

1 DON’T FORGET DIVIDENDS

The Footsie might be 16% lower than in July 1998, but if you include dividends it is in positive territory with a rise of 14%. This is hardly a stellar return — the equivalent of just 1.4% a year — but it does show the importance of reinvesting the income from shares.

Over the longer term, the figures are more convincing: £100 invested in equities 108 years ago would now be worth £209 in real terms without dividends reinvested — a figure that soars to £25,277 with reinvestment, according to Barclays Capital.

2 SHARES WIN OVER THE LONG TERM

Past performance is no guarantee of future returns, but in the long term equities have historically outperformed other asset classes, particularly cash.

In a holding period of two years, equities outperformed cash in 72 out of the past 108 years, giving a probability of equity outperformance of 67%, the Barclays data show. Extending the holding period to 10 years gives a 93% chance of equities outperforming and to 18 years a 99% chance — so if you have been in the stock market for 10 years, hang on for another decade.

3 YOU WILL ACHIEVE YOUR GOALS QUICKER

Over time the benefit of equity investment is obvious. Someone who put £200 per month into a cash account paying 4% per year over 20 years would have saved a total £73,355.

Had the money been invested in shares growing an average 7% per year, they would have £104,185 — £30,830 more. Even if the investment return dropped to just 5%, equities would still beat cash by £8,852.

“The crux of all of this is that if someone wants to save for anything, such as retirement, in cash they need to put aside a lot more money than if they invest in the markets,” said Andy Gadd, head of research at the independent at adviser Lighthouse. “Equity investors must, of course, be prepared to accept the extra risk involved, but that risk is mitigated the longer you’re prepared to invest.”