World equity markets registered their worst month in history as investors lost an estimated $5.79 trillion during October, Standard & Poor's Index Services.

Measured in dollar change to investor held equity accounts, Standard & Poor's data shows that the October loss of the 52 global equity markets was 45% above that of September when markets lost a then record $4.0 trillion. Standard & Poor's estimates that investors have lost $16.22 trillion year-to-date through October.

"What do you get when you add the underlying concern of the economy and the fear of a worldwide recession to a market already devastated by credit issues? You get the worst-ever month for global equity markets in modern history," says Howard Silverblatt, Senior Index Analyst at Standard & Poor's.

"Overlooked, however, is the fact that the U.S. market has been one of the better performing markets over the past five months - although the losses are substantial," adds Silverblatt. "To some extent, the much higher expectations of non-U.S. growth, as well as the expected U.S. decoupling, have caused a much stronger market decline abroad. As a result, the U.S. now represents 45.9% of all global equity issues, compared to 40.5% at the end of May."