Brokers are middlemen, the conduit between the client and the trading venue. That venue may be a regulated exchange or something less secure or transparent. Some brokers simply place the client’s orders into the market place and report on whether it was filled and what price it is trading at.
Some brokers may have discretion to change the price or timing of the order. Ideally, they should do so to get the best possible result for the client.
Other brokers give a higher level of service and advise the client about opportunities and when to enter and exit the markets. Some are registered as Commodity Trading Advisors or fiduciaries. Some broker-advisors may have power of attorney agreements with their clients giving them discretion to trade the client’s account on his or her behalf.
On Nadex, the North American Derivatives Exchange, there are no brokers. All trading is self-directed, meaning individual traders send their orders directly to the exchange. As an exchange, Nadex cannot give any trading advice or recommendations.