Trade Execution Isn’t Instantaneous
Many investors who trade through online brokerage accounts assume they have a direct connection to the securities markets. But they don't. When you push that enter key, your order is sent over the Internet to your broker—who in turn decides which market to send it to for execution. A similar process occurs when you call your broker to place a trade.
While trade execution is usually seamless and quick, it does take time. And prices can change quickly, especially in fast-moving markets. Because price quotes are only for a specific number of shares, investors may not always receive the price they saw on their screen or the price their broker quoted over the phone. By the time your order reaches the market, the price of the stock could be slightly – or very – different.
No SEC regulations require a trade to be executed within a set period of time. But if firms advertise their speed of execution, they must not exaggerate or fail to tell investors about the possibility of significant delays.