How do your responsibilities to a client differ from a broker's responsibilities to a client?
Brokers (or brokers-dealers such as representatives of wirehouses like Merrill Lynch, Morgan Stanley, or UBS) are regulated by the Securities Exchange Act of 1934 which gives self-regulatory organizations (SROs) the ability to regulate their own members. In 2007, the Financial Industrial Regulatory Authority (FINRA) was created to regulate broker dealers.
It is important to remember that FINRA holds its broker-dealers only to a suitability standard, not a fiduciary standard. A suitability standard is a much lower standard and only requires a broker-dealer to make recommendations that are consistent with the best interests of the underlying customer.
For more discussion on the fiduciary vs. suitability standard, click on this link.