Registered representatives--stockbrokers--legally are agents of broker/dealers. In the insurance field, sales representatives--insurance agents--legally are agents of insurance companies.
Under principal/agency law, agents owe the fiduciary duty of loyalty to their principals. Satisfaction of this duty must come first and foremost before any duties that stockbrokers or insurance agents may owe to their clients. In effect, this means that stockbrokers and insurance agents are required by law to maximize the revenue of their principals--whether or not doing so comes at the expense of clients.