A breach of fiduciary duty is a violation of the trust and confidence that is placed in a person or entity to act in the best interests of another. In the context of commercial litigation, a breach of fiduciary duty can occur when a business or individual fails to fulfill their obligations to another party in a way that is not in accordance with the terms of their agreement.

There are several types of fiduciary duties that can be breached, including:

1. Duty of loyalty: This duty requires the fiduciary to put the interests of the other party ahead of their own.
2. Duty of care: This duty requires the fiduciary to act with the level of care and skill that would be expected of a reasonable person in their position.
3. Duty of confidentiality: This duty requires the fiduciary to keep the information of the other party confidential.

In a breach of fiduciary duty lawsuit, the plaintiff (the party bringing the lawsuit) must prove that the defendant (the party being sued) owed a fiduciary duty to the plaintiff, that the defendant breached that duty, and that the plaintiff suffered damages as a result. If the plaintiff is successful, they may be entitled to damages to compensate them for their losses.

Breaches of fiduciary duty can have serious consequences for businesses.