High Internet traffic, market volume, and other systems issues may affect your ability to access your account or transmit your orders and may delay receipt of your order by the brokerage firm. Check with your particular brokerage firm on its notification procedures. And note that notification that the order was received does not mean that the order was executed.
Is my order executed immediately?
Orders entered electronically are usually executed quickly; however, there is no assurance that this will always occur. Investors should be aware that high trading volumes can cause delays in executions. Market volatility and delays in executions due to trading volume can result in trade executions at prices significantly different from the quoted price of the security at the time the order was entered. Also, different firms offer different levels of access and system sophistication. The speed of the Internet Service Provider used by an investor may also have an effect on order transmittal and execution. Timing in execution of orders may also be impacted by market volume, order queues at market centers, possible delays in order transmissions by brokers, and other systems issues.