If you ask most investors at the end of the 2000s, whether they wanted to have international exposure in their portfolios, the answer would have been a resounding, "yes!" Because that was The Lost Decade: where U.S. stocks were flat to even slightly negative, whereas non-U.S. stocks delivered strong returns.
One of the things we've looked at in the data is how rare an occurrence is like that: where you have a 10-year period where a country's equity market is not positive. We looked across 45 different countries's equity markets and looked at the worst decade.
All but six of those 45 countries had had at least one 10-year period that was negative. A lost decade - like what we had in the U.S. - is maybe not that uncommon for a country's equity market. For investors who want to spare themselves of that being in the range of outcomes, global diversification could be a good way to go about doing it.