The Fund invests in financial instruments that ProShare Advisors believes, in combination, should track the performance of the Index. The Index is designed to measure the performance of companies that have business operations in the field of nanotechnology. The index provider uses a natural language processing algorithm to identify companies that fall into one or more of the following categories AS (1) production of nanotechnology, which can be defined as the use of matter on an atomic and molecular level, (2) active in the fields of nanomedicine, nanomaterials, nanoelectronics, nanometrology or molecular nanotechnology, and (3) development of technologies that promote advances in or research related to nanotechnologies.