SPDRs, also known as Standard & Poor's Depositary Receipts or 'spiders,' are securities traded on major exchanges representing ownership in a long-term unit investment trust that holds a portfolio of common stocks. These portfolios are meticulously designed to track the performance of the S&P 500 Index.
A Unit Investment Trust (UIT) is an investment vehicle registered with the SEC under the Investment Company Act of 1940. It purchases a fixed portfolio of securities, which may include corporate, municipal, or government bonds, mortgage-backed securities, common stock, or preferred stock.
