IEF is a longer maturity, longer duration play on the US Intermediate Treasury segment. The fund focuses on Treasury notes expiring 7-10 years from now, which have significantly higher yield and interest rate sensitivity than the notes that make up our broader 1-10 year benchmark. IEF`s average YTM is significantly higher than our benchmark's. Of course, the higher yield comes with significantly higher sensitivity to changes in rates, particularly those at the longer end of the yield curve (10-year key rate duration). The fund changed its index from the Barclays US Treasury Bond 7-10 Year Term Index to the ICE US Treasury 7-10 Year Bond Index on March 31, 2016. This change created no significant change in exposure. IEF's narrow focus and concentrated portfolio have been popular, so the fund is stable and easy to trade.