Alkylate compositions comprising a monoamylphenol in an amount ranging from 25 weight percent to 99 weight percent and a diamylphenol in an amount ranging from 1 weight percent to 60 weight percent, the weight percentages being based on the total weight of all components in the alkylate composition. The invention is also to processes for making such alkylate compositions and to processes for forming stable liquid amylaryl phosphite compositions from such alkylate compositions.