The correlation range runs from positive 1.0 to negative 1.0.

FORBES: Basics of Asset Allocation (Part 2 of 2)

But Mr Montier points out that the correlation of returns from different hedge-fund styles (which invest in a wide range of assets, from corporate bonds through to equities) has risen from around 0.3 in 1993 to 0.8 in 2009.

ECONOMIST: Buttonwood