The EU has recently adopted a new directive on preventive restructuring frame- works, which implements an economic efficiency-based hierarchy of solutions. The concept of insolvent enterprise value is at the core of this brand-new mechanism but is never defined. In a collective proceeding, enterprise value is the result of complex phenomena of competitive pressure. The purpose of this study is to test the applicability and assess the potential contributions of negotiation theory, auction theory, and the theory of negotiauction to the definition of the insolvent enterprise value. Starting with the core concepts of BATNA, reservation value, and ZOPA, building up on the inputs of cognitive sciences, negotiation theory can provide real support to the maximization of value during sale processes in insolvency proceed- ings. At the same time, auction theory offers an interesting overview of the process setter’s responsibility and the importance of transparency and information, as well as simple tools in order to assess possible lost value. Eventually, the theory of negotiauctions provides some more sophisticated techniques in order to deal with value maximization in real world cases and avoid sub-optimal solutions in insol- vency proceedings.