In California, various individuals and entities can be held liable for fiduciary negligence or breach of duty when they violate the high standard of conduct required in a relationship of trust.

Those who can be sued for fiduciary negligence include:

• Corporate Directors and Officers: Individuals who manage the affairs of a corporation and owe duties to the organization and its shareholders.
• Business Partners: Partners in a general or limited partnership who must act in the best interests of the partnership.
• Trustees: Individuals responsible for managing assets for the benefit of named beneficiaries.
• Agents: Persons acting on behalf of a principal in various business or legal capacities.
• Professional Service Providers: This includes attorneys (owing duties to clients) and executors (owing duties to heirs).
• Third Parties: In certain circumstances, parties who do not officially hold a fiduciary title but knowingly aid or abet a fiduciary in committing a breach may also be held liable.

Claims for fiduciary negligence often arise when these individuals exploit their positions for personal gain, fail to disclose conflicts of interest, or fail to exercise the required standard of care (reasonable prudence) in their management roles.