Abbreviated as ETF, refers to a fund that tracks an index, but can be traded like a stock. ETFs always bundle together the securities that are in an index; they never track actively managed mutual fund portfolios (because most actively managed funds only disclose their holdings a few times a year, so the ETF would not know when to adjust its holdings most of the time). Investors can do just about anything with an ETF that they can do with a normal stock, such as short selling. Because ETFs are traded on stock exchanges, they can be bought and sold at any time during the day (In contrast to most mutual funds). The first ETF created was the Standard and Poor's Deposit Receipt (SPDR, pronounced ""Spider"") in 1993. SPDRs gave investors an easy way to track the S&P 500 without purchasing an index fund, and they soon become quite popular.