Maintenance call: A "call" for additional funds or acceptable collateral to be immediately deposited into your margin account to satisfy the Regulation T and house maintenance requirements for the purchase or short sale of securities or as a result of movements in market prices.

Management fee: A charge paid to a mutual fund's managers for their services.

Margin: Using securities you own as collateral to purchase other securities "on credit."

Margin account: A brokerage account that lets you borrow funds to purchase securities, using your own marginable securities as collateral.

Margin balance: The net open balance in your margin account. If the amount is negative, you owe your brokerage firm this amount. If it's positive, the balance may earn interest.

Margin call: A generic term that refers to both maintenance calls and Regulation T calls (also called Reg T or Fed calls). An investor who receives a margin call is required to deposit additional funds or securities in a margin account either because the equity in the account does not meet the brokerage firm's established minimum equity requirement (maintenance call) or because additional securities have been purchased or sold short.

Margin interest: Interest that is charged daily on the balance of your margin loan.

Marginable: A security that may be used as collateral in a margin account.

Marital trust: A trust that is established for the surviving spouse and qualifies for the marital estate-tax deduction.

Market capitalization: The total value of a company's stock. (Number of outstanding shares times the current value of the stock.)

Market indicators: A variety of indexes that are used to determine the overall direction and strength of financial markets.

Market maker: An individual, corporation, partnership or group of firms that maintains inventory of a specific over-the-counter security and stands ready to buy and sell the security at publicly quoted prices. A market maker helps maintain an orderly market.

Market order: An order to buy or sell a stated amount of a security at the best price available when the order reaches the marketplace.

Market price: The last price or current quote at which a security trades in the secondary market.

Maturity date: The date on which the issuer of a bond or certificate of deposit is scheduled to repay the original investment to the bondholder or CD holder. CD maturities typically range between three months and six years, while bond maturities can range from one day to 30 years or more.

Minimum quantity: A condition of an order that specifies the minimum number of shares to be bought or sold by a specialist. Often used when the buyer or seller will accept a partial fulfillment of his or her order.

Minor's trust (2503c trust): An irrevocable trust that enables a grantor to keep principal and income in a trust for the benefit of a child until the child reaches age 21. Principal and income can be expended for the beneficiary. Accumulated income is taxed at trust rates. Assets included in a minor's trust may be excluded from the grantor's estate if the grantor is not a trustee.

Money market account: A type of savings account that invests the available funds in various short-term securities, attempting to maintain a $1 per share value.

Money market fund: An open-end mutual fund that invests in short-term securities such as Treasury bills, certificates of deposit and commercial paper and seeks to maintain a $1 per share value.

Money market mutual fund: An open-end mutual fund that invests in short-term securities such as Treasury bills, certificates of deposit and commercial paper and seeks to maintain a $1 per share value.

Mortgage-backed security: A bond that represents a share in a pool of mortgages issued by U.S. government agencies, U.S. government-sponsored enterprises or mortgage lenders. Investors receive regular (generally monthly) interest payments and the principal is returned incrementally over the life of the investment. (See also CMO and Ginnie Mae.)

Municipal bond: Also called a muni. A bond issued by a state or political subdivision that pays interest, which is usually exempt from federal and, in some cases, state and local taxes. (See also alternative minimum tax.)

Municipal bond funds: A mutual fund that invests in tax-exempt bonds issued by states and municipalities.

Mutual fund: An investment that lets a group of people pool their assets in a mixed portfolio of securities, such as stocks, bonds or money market instruments. An investment company then professionally manages the assets in the portfolio in an effort to achieve a specified investment objective, such as growth or income.

Mutual fund company: An investment company that pools money from shareholders and invests in a variety of securities such as stocks, bonds and money market instruments.

Mutual fund family: The array of mutual funds offered by a single mutual fund company.