Performing well in the areas most dear to investors certainly helped the top three brokers. Trade reliability, site performance and equity trading tools were the most important characteristics after commissions. In all of those, Fidelity, Schwab and TD Ameritrade were the top three in the survey. Fidelity and Schwab also were leading brokerages in customer service. A zone file is a sequence of entries for resource records. Each line is a text description that defines a single resource record (RR). The description consists of several fields separated by white space (spaces or tabs) as follows: The PL chart below graphically shows where this trade will be profitable and at a loss. Mutual funds are subject to market, exchange rate, political, credit, interest rate and prepayment risks, which vary depending on the type of mutual fund.