All day trading markets have margin requirements, but many day traders do not fully understand what margin is, nor what happens when their brokerage makes a margin call.

Margin is nothing to be scared of, as it is simply a financial requirement that is set by the exchange that offers a particular market, but a margin call is something that should be avoided at all costs. If you do not yet know what margin is, or why professional traders should never experience a margin call, full definitions are available in the margin and margin call glossary entries.