Robert Morse
Sponsor
http://www.finra.org/investors/day-trading-margin-requirements-know-rulesWhy was the PDT Rule enacted in 2001.
Why the change?
The primary purpose of the day-trading margin rules is to require that certain levels of equity be deposited and maintained in day-trading accounts, and that these levels be sufficient to support the risks associated with day-trading activities. It was determined that the prior day-trading margin rules did not adequately address the risks inherent in certain patterns of day trading and had encouraged practices, such as the use of cross-guarantees, that did not require customers to demonstrate actual financial ability to engage in day trading.
Most margin requirements are calculated based on a customer's securities positions at the end of the trading day. A customer who only day trades does not have a security position at the end of the day upon which a margin calculation would otherwise result in a margin call. Nevertheless, the same customer has generated financial risk throughout the day. The day-trading margin rules address this risk by imposing a margin requirement for day trading that is calculated based on a day trader's largest open position (in dollars) during the day, rather than on his or her open positions at the end of the day.