• Gold's outperformance signals concern over rising debt

For much of the past half century, US Treasuries have handily outpaced gold as a buy-and-hold investment. Now, bonds' status as the ultimate haven is facing one of its biggest challenges yet.

Investors traditionally flocked to US debt as a super-safe investment paying steady income, and backed by the world's economic powerhouse. For buyers ranging from individual savers to sovereign nations, these attributes made it a superior investment to gold, which doesn't generate cash flows as bonds do, though it is still coveted as a scarce commodity and inflation hedge.