Bipartisan Ban on Congressional Stock Ownership Act of 2023 This bill prohibits Members of Congress and their spouses from owning or trading stocks, bonds, commodities, futures, or any other form of security. Each current Member must divest within 180 days after the bill is enacted and each new Member must divest within 180 days after becoming a Member. However, Members and their spouses have 5 years to divest from specified complex investment vehicles. The bill does not apply to certain investments, such as investments in widely held investment funds that are diversified and do not present a conflict of interest and investments held in government employee retirement plans. A Member or spouse who violates the bill may be subject to a fine of up to $50,000 for each violation. The bill permits a Member or spouse who is required to divest property under the bill to avoid recognizing gain for income tax purposes from the sale of that property to the extent that the Member or spouse purchases permitted bonds or diversified investment funds within 60 days of the divestiture.