Introduction

Abaclat v. Argentine Republic is the first time that a mass claim (in this case, 60,000 Italian bondholders) has been brought in an investment arbitration. This Article considers the propriety of those proceedings from a unique perspective, namely that of regulatory law. In so doing, this Article considers the regulatory nature of class, mass and collective proceedings as well as the regulatory purposes of the investment treaty regime so as to determine whether and to what extent the Abaclat majority acted in accordance with both principles.