Nuveen S&P 500 Buy-Write Income Fund is a diversified closed-ended management investment company based in the United States. Its investment objective is to seek attractive total returns with less volatility. The fund invests its managed assets in a diversified equity portfolio that seeks to substantially replicate price movements of the S&P 500 Index. It also uses an index options strategy of writing (selling) index call options in seeking to moderate the volatility of returns relative to an all-equity portfolio. Its revenue is generated mainly from interest and dividend income.