TBT is a choice for levered bets on rising interest rates. Using a combination of swaps and futures, TBT gives investors -2x exposure to daily moves in T-bonds with more than 20 years left to maturity. The daily reset means investors shouldn't expect the leverage factor to hold constant over investment horizons greater than one day. In short, the fund is a valid option for tactical positioning/hedging against rising interest rates, but it's important to keep in mind that the -2x leverage results in greater impact from the effects of compounding. As a levered product, TBT is not a buy-and-hold ETF, it's a short-term tactical instrument. On Oct. 14, 2016, TBT changed its underlying index from Bloomberg Barclays U.S. 20+ Year Treasury Bond Index to ICE U.S. Treasury 20+ Year Bond Index. The change had minimal impact on investors exposure.