The Barclays Capital U.S. Aggregate Bond Index is an investment-grade domestic bond index.

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It makes sense for the investment-grade bond index to do better once its worst credit has dropped out.

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That said, the Bank of American Merrill Lynch High-Grade Bond Master Index is up 3.75% through April 30 as a result of spread compression across the credit markets from the more lofty levels of the fourth quarter.

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Carlson has delivered a 13% compound annual return since then, a percentage point better than the emerging market index and better than double what you would have earned from the collection of high-grade U.S. paper in the Vanguard Total Bond Market Index Fund .

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The JPMorgan Domestic High Yield Index is an index composed of non-investment-grade corporate bonds.

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The average yield for nonfinancial company bonds in the iBoxx Euro corporate index, which measures the performance of investment-grade debt issued in euros, is around 2.35%, Markit said.

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Emerging market and investment grade bonds have sold off in the last few days, and the dollar high-yield index has plateaued, but European high-yield has remained on course, edging higher.

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Consider that the Barclays Municipal Bond Index (the most popular industry benchmark) is comprised of predominantly longer-maturity, higher-grade debt.

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