This article discusses new index-based investments known as "geared beta" strategies. These strategies employ derivative instruments to achieve dramatic outperformance of market returns. Mutual funds which use enhanced indexing strategies can be classified as follows: those that employ securities-based enhancement and those that employ derivatives-based enhancement. Geared beta strategies fall within the second category. The article also briefly explains the other types of derivatives-based index enhancement, including derivatives arbitrage, option overwriting and portable alpha strategies. Geared beta strategies are distinguished from other index enhancement techniques as they have specific objectives that are generally quantified according to index sensitivity (beta). In addition, the article examines geared beta strategies in the context of the over-arching duty of fiduciaries to act prudently when investing the assets entrusted to them. In particular, fiduciaries need to be aware of the compounding nature of the returns generated by geared beta strategies (which typically seek to exceed the daily performance or inverse daily performance of a benchmark index).