If you use a margin account, you are subject to the .
Buying and selling the same security on the same day is considered a . On E*TRADE, your ability to do this depends on whether you have a Cash or Margin account, as different rules apply to each. 1. Margin Accounts & The Pattern Day Trader (PDT) Rule
: You are limited to 3 day trades within a rolling 5-business-day period.