Is your target-date fund ripping you off?

Meanwhile, the younger investors in the Target 2050 funds are decades away from retirement and should be in funds with returns that are on the higher end of the range.

FutureAdvisor also found that, on average, funds that charged higher fees had significantly lower annual returns than their cheaper alternatives.

Take this example of one-year average returns for low-, middle- and high-cost funds in 2014 for workers nearing retirement this year.

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Factset: FactSet Research Systems Inc. 2015. All rights reserved.

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