How should the doctrine of unilateral mistake apply when a programming error results in a buyer's algorithmic trading programme accepting an offer generated by the seller's trading programme to exchange cryptocurrencies at 250 times the current market rate? How should the knowledge element be adapted given that algorithmic trading necessarily means that the traders’ minds were not engaged at the moment the contract was formed? These novel issues came before the Singapore Court of Appeal in Quoine Pte Ltd v B2C2 Ltd. [---]