Elroy Dimson

Everybody can, to some extent, benefit except those who go into the stock market where prices already reflect the consensus as to what the future holds.

I think that's been very important.

Again, if you go back a long way,

Almost every country had a small number of sectors which were important.

Some had a very small number of stocks that were important.

It was difficult to get a broad portfolio.

Over the years, two things were happening.

but there were more and more industry sectors.

So if you were to look within one large market, such as the United States, there was much more opportunity to create a diversified portfolio because businesses that used to be private by then were listed.

And if we think about investing globally, then you could spread the risks that are associated with particular countries or are associated with the resources that particular countries have.

and diversify those much more effectively.

So there's a lot of risk, which you might have thought is inherent to investing.

And it turned out a lot of that could be diversified away.

You can spread your money around in a way which eliminates many elements

in the middle of the last century.

Diversification has been important, and it's been important as there's been a growth in varied investment opportunities.

Some people would say that now, because of the very largest companies, there's a little bit less opportunity.

A quarter of the global equity market is represented by just 10 companies.

Of those 10, 9 are in one country, the United States, and one is in Taiwan.

You would like to diversify.