One might expect an all-star conference hosted by former junk bond king Michael Milken to be full of boosters for the riskier side of the credit markets, but not a bit of it. The prevailing mood this week at Mr. Milken’s annual gathering in Los Angeles was of caution about the lack of yield from the so-called high-yield market.

The simple reason for caution is that at 5.7%, high-yield bonds just don’t offer a high yield, even relative to the low yield available from supersafe U.S. Treasurys.

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