Unlike most, billionaires have more money than they can spend in a lifetime.  Hence they have a higher risk tolerance for losses and tend to hold a lot of assets of all kinds.  This has made them ideally situated to benefit from the $9 trillion of central bank injections into financial markets over the past 14 months.  At the same time, these same forces have increased the correlation between global asset classes as well as social and economic vulnerability to price declines.  Historically, such extreme imbalances have been followed by giveback periods of one kind and another.