The ProShares Short 20+ Year Treasury ETF (TBF) is an exchange-traded fund (ETF) that seeks daily investment results, inversely (-1x) of the performance of the ICE U.S. Treasury 20+ Year Bond Index. The fund is managed by ProShare Advisors LLC and was launched in 2009.

The ICE U.S. Treasury 20+ Year Bond Index is a market-capitalization-weighted index that measures the performance of U.S. Treasury bonds with maturities of 20 years or more. The index includes both on-the-run and off-the-run bonds.

TBF is an inverse ETF, it uses derivatives to invert its exposure to the underlying index. This can lead to significantly good returns under certain conditions.