One Sided Market - A market condition where there are significantly more sellers than buyers or more buyers than sellers. In this case, there are not enough buyers putting up offers to buy from sellers or that there are not enough sellers putting up offers to sell to buyers.

Open Interest - The net total of outstanding open contracts in a particular option series. An opening transaction increases the open interest, while any closing transaction reduces the open interest. Read More About Volume and Open Interest.

Option - The right to buy or sell specific securities at a specified price within a specified time. A put gives the holder the right to sell the stock, a call the right to buy the stock.

Optionable Stocks - Stocks with tradable options.

Option Pricing Curve - A graphical representation of the projected price of an option at a fixed point in time. It reflects the amount of time value premium in the option for various stock prices, as well. The curve is generated by using a mathematical model. The delta (or hedge ratio) is the slope of a tangent line to the curve at a fixed stock price.

Option Trader - Also known as Options Trader. It is anyone who buys and sells options in the capital market. Read more about Option Trading.

Option Trading - Also known as Options Trading. It is the buying and selling of stock and index options in the capital market so as to speculate for leveraged profits in every market condition or perform hedging to reduce portfolio risk. Read more about Option Trading.

Options Clearing Corporation (OCC) - The issuer of all listed option contracts that are trading on the national option exchanges.

Options Trading - The buying and selling of stock and index options in the capital market so as to speculate for leveraged profits in every market condition or perform hedging to reduce portfolio risk. Read more about Options Trading.

Options Trader - Anyone who buys and sells options in the capital market. Read more about Option Trading.

Options Strategist - An investment professional who specializes in research, analysis and execution of options strategies.

Out of the Money - Describing an option that has no intrinsic value. A call option is out-of-the-money if the stock is below the strike price of the call, while a put option is out-of-the-money if the stock is higher than the strike price of the put. Read More About Out Of The Money Options.

Over-the-Counter Option (OTC) - An option traded over-the-counter, as opposed to a listed stock option. The OTC option has a direct link between buyer and seller, has no secondary market, and has no standardization of striking prices and expiration dates.

Overvalued - Describing a security trading at a higher price than it logically should. Normally associated with the results of option price predictions by mathematical models. If an option is trading in the market for a higher price than the model indicates, the option is said to be overvalued.