Investors are naturally biased to their home market, but those who don't venture overseas are limiting their investment returns, according to figures calculated by Telegraph Money.

A typical investor holds around 26pc of their portfolio in London-listed stocks, despite the UK only accounting for 7pc of the global market, according to investment firm Vanguard.

Some savers will be far more dependent on the UK than that.

Many large UK firms derive large proportions of their income from overseas, but even still, over five, 10 and 15 year time frames, investing in shares listed globally has proven a huge advantage.

Using data service FE Analytics, we compared the returns of four indices:

FTSE 100: representing the UK’s 100 largest companies.

FTSE All Share: a broader representation of the UK market, including mid-sized and smaller companies.

FTSE Developed World: representing a number of developed markets in North America, Europe, Asia and Australasia.

FTSE All World: representing a wide range of global markets, including developed and emerging nations.

For all three time scenarios, the FTSE All World index had the greatest total return by a significant margin. At the end of 15 years, it returned 330pc, compared to 204pc for the FTSE 100 and 237pc for the FTSE All Share.