There’s nothing more beautiful to a professional investor than a negative correlation between stocks and bonds. When stocks have a bad month, bonds have a good month, and vice versa. Since their zigs and zags offset each other, the value of the combined portfolio is less volatile. The customers are pleased. And that’s how it’s been for most of the last two decades.
But for almost a year now, Bloomberg market reporters have been detecting anxiety from the pros that the era of negative correlation may be over or ending, replaced by an era of positive correlation in which stock and bond prices move together, amplifying volatility instead of dampening it. “Bonds Have Never Been So Useless as a Hedge to Stocks Since 1999,” read the headline on one article this May.