To track the performance of Bloomberg US Short Treasury Index (the "Index"), and to minimize the tracking error between the net asset value of the sub-fund and the performance of the Index. The Bloomberg US Short Treasury Index is a bond index representative of USD-denominated bills, bonds and notes issued by the US government. The index includes treasury bills issued in fixed maturity terms of 4, 13, 26, and 52 weeks and treasury notes and bonds that have fallen below one year to maturity.