Abstract.   Traditionally, liability for the breach of the duty of investment where a trustee made an unauthorised investment was dealt with in terms of the trustee’s liability to account; in particular, the beneficiary could falsify the account, with all that entailed regarding the rules of ‘restoration of the trust fund’. However, recent decisions, in particular the UKSC decision in AIB Group (UK) Plc v Mark Redler & Co Solicitors [2014] UKSC 58 and the HKFCA decision in Akai Holdings (in liquidation) [2011] 1 HKC 357, suggest that henceforth liability is to be assessed on a ‘but for’ consequential loss basis, in view of the fact that the transactions at issue were essentially commercial or contractual in nature. It is argued that this suggestion cannot be treated as a general alteration of the rules of trustee liability in such cases, and furthermore that the principles applying to breach of contract were not adequately explored in these decisions.