Who Are Typical Defendants in Securities Litigation?
Video Summary (from YouTube): Broker Negligence Leading to Investment Loss
The typical defendants in securities litigation would be a financial advisor and the firm that he worked for.
It could also be an investment advisor that has no affiliation with the brokerage firm. It could be a trustee of a trust company.
Anyone that has a position of taking care of your assets for you that you've hired and has either done a poor job through negligence, or has fraudulently hurt you is a potential defendant.