A rheology modifier obtainable by polymerizing (i) at least one ethylenically unsaturated carboxylic acid; (ii) at least one nonionic ethylenically unsaturated surfactant monomer, (iii) at least one C1-C2-alkyl methacrylate, and (iv) at least one C2-C4-alkyl acrylate, where the alkyl chain length averaged over the number of alkyl groups of the alkyl acrylate is 2.1 to 4.0. The polymerization is carried out in the presence of at least one hydrocarbon comprising at least one XH-group, wherein X is selected from the group consisting of O, P, N and S. Liquid formulations and particles containing liquid detergents comprising the rheology modifier are also described.