Your individual trading style will determine which broker is best for you. While we continually urge traders to limit their trading strategies to two or at the most three strategies, we find that many successful traders use two or three, some even four or five brokers. Don't limit yourself to only one broker.
Some brokers focus on different segments of trading.
For example, some brokers don't offer option trading, others don't offer the Level II Quotes that daytraders require. Some full-time daytraders like to have multiple accounts set up just as a safeguard in case their favorite broker experiences trouble of some sort. There are several things you will want to consider when you choose a broker. Some otherwise excellent brokers do not have competitive margin rates. Most brokers will pay you interest on the money in your account when you don't hold any positions and some will even sweep your funds into a money market to get you a better rate.