Open-end Mutual Fund
A type of fund that issues as many shares as investors demand. Most mutual funds are open-end funds.

Options
An agreement allowing an investor to buy or sell something, such as shares of stock, during a specific time for a specific price. Options are traded on several exchanges, including the Chicago Board of Options Exchange.

Over-the-counter Market
A market in which securities transactions are conducted by dealers through a telephone and computer network connecting dealers in stocks and bonds.

Over-the-counter Securities
Securities that are not listed and traded on an organized exchange.