Margin
A process which a brokerage client uses credit to finance securities transactions. The Federal Reserve System regulates the extent of margin borrowing by setting the margin rate.

Margin Account
A brokerage account allowing customers to buy securities with money borrowed from the brokerage.

Margin Call
A demand upon an investor to put up more collateral for securities bought on credit. The lender, usually the brokerage firm, makes the call when the equity in the investor's account falls below the level set by the brokerage.

Margin Rate
A constant value added to the index rate of an adjustable-rate mortgage to compute the current interest rate.

Marginal Tax Rate
The tax rate you would owe on your next dollar of taxable income. This can be highly valuable information when you are making investment decisions.

Marital-deduction Trust:
A trust set up to receive money left to a spouse under the unlimited marital deduction and to impose some restrictions on those funds. The term of the trust may require use of certain financial advisers, for example, or may protect assets from possible claims should the surviving spouse remarry.

Market Capitalization
The total market value of a company or stock. Market capitalization is calculated by multiplying the number of shares by the current market price of the shares.

Market Maker
In a stock market, a trader responsible for maintaining an orderly market in an individual stock by standing ready to buy or sell shares. On a stock exchange, a market maker is known as a specialist.

Market Order
Order to buy or sell a security at the market price.

Market Risk
Volatility associated with general market movement. Not diversified within the market.

Market Timing
Shifting money in and out of investment markets in an effort to take advantage of rising prices and avoid being stung by downturns. Few, if any, investors manage to be consistently successful in timing markets.

Maturity
The date on which an issuer fulfills its final obligation (s) to the holders of its debt securities by returning the investors' principal and perhaps a final interest payment.

Maturity Date
When a bond expires and the loan must be paid back in full.

Mezzanine Financing
A leveraged buyout or restructuring financed through subordinated debt, such as preferred stock or convertible debentures. It is popular in mergers and acquisitions, because the transaction is financed by expanding equity, as opposed to debt. Holders of the securities created by this method often have a greater role in managing the resulting company. May also refer to second- or third-level financing for companies that have been funded with venture capital.

Monetary Policy
A government's efforts to control its money supply.

Money Market Account
A federally insured account available at many banks, credit unions and savings and loan associations.

Money-market Fund
A type of mutual fund that invests in stable, short-term securities. Money funds are easily convertible into cash and usually maintain an unchanged value of $1 a share, but are not insured by the federal government.

Mortgage Bonds
Debt security for which specific collateral is pledged.

Municipal Bonds
Bonds issued by local-government authorities, including states, cities and their agencies.

Mutual Fund
Companies that buy and sell investment assets with the gains and losses accruing to the owner. The shares are redeemable on demand at their net asset value. A fund invests pooled assets into various investment vehicles including stocks, bonds, options, commodities and money market securities. Investments are determined by the fund's objectives. The mutual fund's prospectus details this type of information plus information on any fees, the management company and other relevant data. Diversification and liquidity are key benefits of Mutual Funds.