Strategists at Bank of America Corp. recently got their hands on US bond market data going all the way back to the founding of the nation. And it shows, they say, that never before has there been an extended period of losses like the past three years.

It's hard to know, of course, just how accurate the figures were from those early post-colonial years. (How often could bonds have traded during the War of 1812?) Still, there's something jarring about a worst-in-236-years statistic.