Spiders (SPDRs)

SPDRs stand for Standard and Poor’s Depositary Receipts. Known as "Spiders," a SPDR is a unit investment trust that holds shares of all of the companies in the Standard & Poor’s 500 Composite Stock Price Index (S&P 500). SPDRs closely track the price performance and dividend yield of the S&P 500. There are also SPDRs that represent other indexes or particular industry groups.

Investors who purchase a SPDR own approximately one tenth of the value of the S&P 500 and receive pro rata quarterly dividends less expenses of the trust. Unlike an index mutual fund that can only be bought and sold at the end of each trading day, SPDRs trade throughout the trading day.

You can find more information about SPDRs at the website of the American Stock Exchange.