Day Orders
Unless an investor specifies a time frame for the expiration of
an order, orders to buy and sell a stock are “day orders,”
meaning they are good only during that trading day.
To understand where and how an order you
place with your broker is executed, you should read Trade Execution: What Every Investor
Should Know. For
more information on the different types of orders you can place when you buy or
sell a stock, please read our investor bulletin “Trading Basics”.
http://www.sec.gov/answers/dayord.htm