It's rarely been a better time for borrowers with good credit totap into the bond market. In fact, the same is true for borrowerswith dodgy credit.

It's not just U.S. Treasuries that are seeing near-historic-lowyields. Once-radioactive sovereign markets like Greece, high-taxU.S. states like New York and California, and corporate borrowersfrom investment grade to junk are being rewarded with yields thatare barely above benchmarks.

With the record-long U.S. economic expansion on course to entera 12th year, a swollen supply of investor capital flooding intomarkets is shrinking or eliminating risk premiums throughout thefixed-income landscape. It's not that investors are oblivious tothe eye-popping valuations. In fact, "bond bubble pops" was thesecond-most-cited risk in Bank of America's latest survey of fundmanagers. Regardless, many investors ask: What choice do they havebut to keep on buying?