This is mentioned within the introduction of the statement made by Arrowgrass LLP. It says "This statement is made by all subsidiaries and affiliated entities in the Arrowgrass group (together “Arrowgrass”)pursuant to section 54 of the Modern Slavery Act 2015 (the “Act”) and in respect of the financial year ended 31st December 2018." This shows it was made in concordance with the modern slavery act in 2015.