Maintenance Margin: A set minimum margin (per outstanding futures contract) that a customer must maintain in his margin account.

Managed Account: See Discretionary Account.

Managed Futures: Represents an industry comprised of professional money managers known as commodity trading advisors who manage client assets on a discretionary basis, using global futures markets as an investment medium.

Margin: See Clearing Margin and Customer Margin.

Margin Call: A call from a clearinghouse to a clearing member, or from a brokerage firm to a customer, to bring margin deposits up to a required minimum level.

Market Information Data Inquiry System (MIDIS): Historical Chicago Board of Trade price, volume, open interest data and other market information accessible by computers within the Chicago Board of Trade building.

Market Order: An order to buy or sell a futures contract of a given delivery month to be filled at the best possible price and as soon as possible.

Market Price Reporting and Information System (MPRIS): The Chicago Board of Trade's computerized price-reporting system.

Market Profile®: A Chicago Board of Trade information service that helps technical traders analyze price trends. Market Profile consists of the Time and Sales ticker and the Liquidity Data Bank.

Market Reporter: A person employed by the exchange and located in or near the trading pit who records prices as they occur during trading.

Marking-to-Market: To debit or credit on a daily basis a margin account based on the close of that day's trading session. In this way, buyers and sellers are protected against the possibility of contract default.
Minimum Price Fluctuation: See Tick.

Money Supply: The amount of money in the economy, consisting primarily of currency in circulation plus deposits in banks: M-1–U.S. money supply consisting of currency held by the public, traveler's checks, checking account funds, NOW and super-NOW accounts, automatic transfer service accounts, and balances in credit unions. M-2–U.S. money supply consisting of M-1 plus savings and small time deposits (less than $100,000) at depository institutions, overnight repurchase agreements at commercial banks, and money market mutual fund accounts. M-3 –U.S. money supply consisting of M-2 plus large time deposits ($100,000 or more) at depository institutions, repurchase agreements with maturities longer than one day at commercial banks, and institutional money market accounts.

Moving-Average Charts: A statistical price analysis method of recognizing different price trends. A moving average is calculated by adding the prices for a predetermined number of days and then dividing by the number of days.

Municipal Bonds: Debt securities issued by state and local governments, and special districts and counties.