Margin Call: There are two types of margin calls, and they all require to be recovered by depositing additional assets (storing cash or sufficient financingable stocks) and/or closing enough existing securities to cover the recovery notice.  The first type of fmargin call occurs when you open a position to buy/sell new securities that do not meet the initial financing margin maintenance requirements.  This is known as the Federal Reserve Board  Regulation T Recovery Notice (Regulation T Call).  Another type of margin call is that the personal assets that occur in your account are not sufficient to hold the securities that are now open.  This is known as the Maintenance Finance Call  Notice (Maintenance Call).