there's inverse ETF's. SPXS is a leveraged "bear fund" that gains value as the S&P500 decreases in value. SPXS is particular will move 3X the movement of the S&P500 so a loss of 1% in the market is a gain of 3% in SPXS.
SPXS has been an awful fund to hold since 2009.
Be careful with leveraged ETFs because of decay. They are really only good to hold short periods.