UNCITRAL Working Group III (WGIII) on Investor-State Dispute Settlement (ISDS) Reform continued its work with two sessions in the first quarter of 2025. Its 50th session took place in January, discussing procedural and cross-cutting issues and a draft statute of a standing mechanism for the resolution of international investment disputes. The 51st session in New York was divided into two parts, one in February and the other in April. The topics discussed in the first part were the multilateral instrument to implement WGIII reform products and the operationalization of the Advisory Centre, whereas the second part continued the work on topics discussed during the 50th session. During these sessions, the Secretariat has published three unofficial documents reflecting work in progress, among which are the Draft Guidelines on the Calculation of Damages and Compensation in ISDS, that contain recommendations about the organization of the arbitral proceedings when it comes to damages calculation, the burden of proof, causation, standard of compensation, state defenses, valuation methods, interest, and allocation of costs. (The Academic Forum on ISDS Reform also shared a draft paper on the same topic during the second part of the 51st session, here). The other two unofficial documents deal with the draft provisions on procedural and cross-cutting issues and the draft statute of a standing mechanism.