Leveraged exchange-traded funds (LETFs or leveraged ETFs) attempt to achieve daily returns that are a multiple of the returns of the corresponding index. Leveraged index ETFs are often marketed as bull or bear funds. For example, a leveraged bull ETF fund might attempt to achieve daily returns that are 2x or 3x those of the Dow Jones Industrial Average or the S&P 500 Index. A leveraged inverse exchange-traded fund may attempt to achieve returns that are -2x or -3x the daily index return, meaning that it will gain double or triple the loss of the market. To achieve these results, the issuers use various financial engineering techniques, including equity swaps, derivatives, futures contracts, and rebalancing, and re-indexing.