The two most important works in blockchain and antitrust have been written by Professor Thibault Schrepel, both published in 2019. Schrepel’s works explain in detail how blockchain works and why consensus rules can help create opportunities for both unilateral abuses and collusion.

In this article I rely on Professor Schrepel’s in-depth conceptual explorations of blockchain to limit the discussion of the use of the technology in conspiracies in restraint of trade, particularly cartels. This article complements Professor Schrepel’s observations by shedding light on how consensus rules can be built to automatically erase or create a hard fork for sensitive information when immutability no longer interests the parties to a cartel.

By elaborating on how shifting from immutability to mutability and vice-versa is the most relevant feature to turn blockchain into an unprecedented threat to fight cartels, this paper complements Professor Schrepel’s observations on how blockchain can enhance opacity for outsiders and at the same time improve transparency for cartel members.