Exchange-traded funds, or ETFs, are funds that is sold and sold like products. They aren't exactly like stocks, however, because are inclined to focus on groups of stocks as well as market like a whole, rather than on individual companies. They have also been usually higher priced to trade because you have to pay fees on the surface of trading commissions when get and sell them. But they've provided a brand new world of money-making chances to investors, even the shorting of sector futures.

https://www.instapaper.com/p/6620601