SPXS is an extremely aggressive bet against the S&P 500, promising to provide -300% of the index's return for a one-day period. The fund, like most geared inverse products, is designed to deliver its 3x inverse exposure to the S&P 500a cap-weighted basket of 500 of the largest firms in the USfor one trading day. Holding it for a period longer than that will introduce the effects of compounding, a dynamic that's increasingly pronounced as you add more leverage to the strategy. If the fund is held more than one day, your position will need to be adjusted daily to maintain the -3x multiple. Investors should be comfortable with not just the mechanics of the portfolio but the counterparty risk it takes on to get its exposure: SPXS holds swaps on the index to achieve its goals.
