Self-trading is an act in which an offender abuses his position in two or more business entities that are in a competitive position with each other, in order to enrich himself or another person. One of the major business entities in the financial market is banks, which provide clients with banking transactions as part of their business activities. Banks usually protect themselves against similar conduct of their employees or other persons working with them by a competition clause, which prohibits these persons from operating for other banks. In the event that the offender abuses his position in two or more banks, he may not only violate the said private law prohibition of competition, but his actions may fulfill the facts of the criminal offense of abuse of position in business dealings under Section 255a of the Criminal Code. This contribution is focused on the abuse of business position, the fulfillment of which may occur in the implementation of banking transactions.