This investment vehicle aims to replicate the returns of the S&P AMT-Free Municipal Series 2020 IndexTM. The fund generally commits a minimum of 90% of its assets to the municipal bonds that constitute its benchmark index. Up to 10% of its holdings may be allocated to derivative contracts such as futures, options, and swaps, or held as cash and liquid equivalents. Additionally, the fund manager has the flexibility to invest in securities not directly part of the index, if deemed beneficial for maintaining accurate index correlation. The underlying index itself tracks the performance of highly-rated, non-redeemable U.S. municipal debt instruments that are all set to mature in the year 2020.