Investors who are considering AllianceBernstein fixed-income mutual funds can consider factors such as risk-adjusted returns, expense ratios and management tenure. The AllianceBernstein Global Bond Fund Class A Shares ("ANAGX"), AllianceBernstein Intermediate Bond Class Fund I Shares ("ABQIX") and AllianceBernstein Unconstrained Bond Fund Class I Shares ("AGLIX") all offer exposure to fixed-income securities with superior performance statistics relative to their respective category averages. However, each has a different strategy and composition, leading to variations in relative performance over time.

Global Bond Fund (ANAYX)

The AllianceBernstein Global Bond Fund generally invests assets in fixed-income securities issued by non-U.S. companies, though the fund is authorized to hold government bonds and notes issued by U.S. entities. At least 75% of the portfolio must be investment-grade, according to the fund prospectus.

As of April 2016, the fund had three-year average returns of 2.13%, five-year returns of 3.71% and 10-year returns of 5.66%. These figures are very similar to the returns of the benchmark Barclay's U.S. Aggregate Bond Total Return, though the fund outperformed the benchmark by 74 basis points (bps) over the 10-year span. The fund's performance was even better in comparison to the world bond category benchmark, exceeding three-year returns by 219 basis points, five-year returns by 217 basis points and 10-year returns by 138 basis points.

Relative to the Barclay's U.S. Aggregate Bond Total Return Index, the fund had a three-year alpha statistic of negative 0.09, with a five-year alpha of 0.47 and 10-year alpha of 0.44. The world bond category benchmark had corresponding alpha statistics of negative 2.17, negative 1.27 and negative 1.03. The fund's alpha suggests that management is providing value beyond its benchmark performance. The fund has a four-star rating from Morningstar.

Intermediate Bond Fund (ABQYX)

The AllianceBernstein Intermediate Bond Fund invests in short- and long-term fixed-income securities, with average duration of three to six years. Up to 25% of the fund may be invested in below-investment-grade bonds and foreign holdings. Holdings and trades are made based on advisor discretion in this actively managed vehicle.

As of April 2016, the fund had three-year average returns of 2.47%, five-year returns of 3.88% and 10-year returns of 5.15%. These values all surpassed the Barclay's U.S. Aggregate Bond Total Return benchmark returns, and the fund exceeded the intermediate-term bond category average by 74 bps over three years, 43 bps over five years and 57 bps over 10 years.

Relative to the Barclay's U.S. Aggregate Bond Total Return Index, the fund had alpha statistics of 0.15 over three years, 0.27 over five years and 0.03 over 10 years. The corresponding intermediate-term bond category benchmark alphas were negative 0.45, 0.14 and negative 0.07. The fund's Sharpe ratios of 0.83 over three years, 1.36 over five years and 0.93 over 10 years also topped the category average in each period. Like the Global Bond fund, this fund has a four-star rating from Morningstar.

Unconstrained Bond Fund (AGSIX)

The AllianceBernstein Unconstrained Bond Fund holds fixed-income securities and related derivatives with a dynamic allocation strategy. As such, the portfolio's constitution can vary significantly over time, with combinations of corporate and government bonds issued by domestic and foreign entities with different risk profiles. At least half of the fund's portfolio is usually dedicated to investment-grade bonds.

As of April 2016, the fund had average returns of 0.44% over three years, 2.73% over five years and 3.29% over 10 years, which lag the figures posted by the other two funds. These returns lagged the Barclay's U.S. Aggregate Bond Total Returns index, but the fund outperformed the nontraditional bond category index by 31 bps over three years, 161 bps over five years and 334 bps over 10 years.

Relative to the Barclay's U.S. Aggregate Bond Total Return index, the fund's three-, five- and 10-year alpha statistics lagged the category benchmark, though positive alpha over the five- and 10-year periods indicates value added by the investment strategy. The fund had Sharpe ratios of 0.17 over three years, 0.88 over five years and 1.17 over 10 years ended April 2016, all of which exceeded those of the category benchmark. Like the other two funds, the Unconstrained Bond fund earned the fund a four-star rating from Morningstar.

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