Unauthorized Trading
A broker who buys or sells securities in an investor's account without
the prior consent of the investor has engaged in unauthorized trading.
Investors must consent to a purchase or sale of a security in their
account, unless they have given the broker written discretionary
authority (which is rare) to make transactions on their behalf. Even in
the case of discretionary accounts, a broker cannot misuse or exceed
that authority and make a commission on trades he or she was not
authorized to make. Unidentifiable debits or credits on monthly
statements may be an indication that a broker has traded securities
without proper authorization.
Misrepresentation/Omission
Misrepresentation involves a breach by the broker of his duty of
good faith not to misrepresent any "material" fact to the investor in
the sale or recommendation of an investment. Material facts include
facts that address the nature or quality of the investment or the
degree of risk involved . An "omission" is similar, but in that
situation, a broker has failed altogether to disclose a fact material
to the investor's decision-making process.
Overconcentration
One of the most important rules of investing is diversification of
an investor's portfolio to provide protection against a decline in
value of one particular investment. If a broker concentrates an
investor's funds in any individual investment or type of investment -
only high-risk stocks, for instance - then the risk associated with the
portfolio is dramatically increased.