Investment Glossary

Welcome to Firstrade’s stock trading terms glossary. Do all the research you want. Use this glossary to look up the definition of any financial term.
- O -

The investment strategy of a mutual fund as stated in the prospectus.

Odd Lot

A quantity of securities smaller than 100 shares, which is considered the standard unit of trading.


The lowest price at which an investor or dealer is willing to sell shares of a security.

Offer Price

See Offer.

Offer Price (Mutual Fund)

The purchase price of a load fund, calculated by adding the fund's sales charges to its net asset value.


See Original Issue Discount.

On-Balance Volume Index

This is the ratio of volume to upward price movement, used in technical analysis to determine if a security is being heavily bought into or sold out of.

Open-End Fund

A mutual fund that continuouslys offer shares and stands ready to buy any shares redeemed by the shareholders.

Open-End Management Company

A management company that constantly issues new shares.

Open Interest

The number of outstanding option contracts for a particular class or series currently in the exchange market.

Open Outcry System

The public auction in trading pits of exchanges that involve verbal bids and offers.

Opening Purchase

A transaction made by an investor with the intention of creating or increasing a long option position.

Opening Sale

A transaction made by an investor with the intention of creating or increasing a short option position.

Opening Transaction

An investor either buying or selling an option contract to open a new position.

Operating Margin

A company's profitability before non-cash charges, it is a measure of a company's operating efficiency. Operating margin is calculated by dividing EBITDA by revenues then multiplying by 100.


OPG orders are qualified as At-the-Open. An OPG qualifier requests that your order will be executed as close to the opening price as possible. The order will be accepted if it is received before 9:15AM (ET). The order can be cancelled after 9:15AM, but it cannot be edited. After 9:28AM, OPG orders cannot be edited or cancelled. Any unfilled orders after opening of the market will be cancelled.


A contract that gives the buyer the right to buy (call) or sell (put) a predetermined quantity of an underlying security during a specific period of time at a predetermined price.

Option Adjustments

Adjustments made to the terms of an option contract to reflect changes in the underlying security, such as a dividend payment or split.

Option Agreement

The agreement the client must sign to trade options.

Option Class

The group of options with the same underlying security.

Option-Income Fund

A mutual fund which tries to generate additional income by continuously writing options.

Option Series

The groups of options that have same strike price, expiration date, and unit of trading on the same underlying stock.

Options Clearing Corporation (OCC)

A clearing corporation owned jointly by the major exchanges of listed options. Any options traded on any SEC-regulated exchange can be settled through OCC.

Order Book Official

An employee of an exchange who maintains a book of public orders and executes limit orders on behalf of the membership.

Ordinary Shares

The most common form of shares, also known as common stock.

Original Issue Discount (OID)

The discount from par value when the bond is first issued.

Original Issue Zeros

Zero-coupon securities that were originally issued by a corporation or government as a zero-coupon bond, instead of by severing interest and principal payments from an existing bond.


See Over-the-Counter Market.

OTC Bulletin Board

An electronic service that provides selected quotes on over-the-counter stocks.

Other Current Assets

Accounting term describing the value of non-cash assets, including prepaid expenses and accounts receivable due within the year.


An option is out-of-the-money if the price of the underlying security is below the strike price of a call option, or above that of a put. The holder would suffer an immediate loss if he was to exercise the right and purchase or sale the underlying security.

Overbought\Oversold Indicator

An indicator which attempts to define when prices have moved too rapidly in either direction and thus are vulnerable to reaction.

Over-the-Counter Market (OTC)

Comprised of a network of telephone and telecommunication systems over which unlisted securities and other issues trade.