Junk Rout Conundrum: If No One Gets It, Do I Buy or Sell?

As junk bonds plunge in value, many investors are wondering why.

There’s no obvious explanation for the 1.5 percent decline in U.S. high-yield securities in the past month, or the $9.9 billion of cash pulled from mutual funds that buy the debt. The most likely reason is that investors are increasingly uncomfortable hanging onto bonds that are expensive by historical measures.