A buy and sell agreement stipulates how a partner's share of a business may be transferred should that partner die or leave the business. Structure the buyout properly.A properly structured and funded buysell agreement enables an orderly transfer of the business. This structured approach solidifies the agreement's legality and assures everyone of the buyout's successful execution. Conclusion. In a stock sale, the entire company, including all assets and liabilities, is sold to a new owner.