Exchange traded funds have been called the next generation of mutual funds. Essentially, ETFs are low cost, tax-efficient index funds that trade on a stock exchange. In 1999, there were 33 ETFs trading on North American stock exchanges with assets of US$39.6 billion. Five years later, despite going through the worst equity bear market in 70 years, ETFs number over 300 and assets have soared in excess of US$300 billion globally.