Aspects of the invention provide single stranded oligonucleotides for activating or enhancing expression of a target gene. Further aspects provide compositions and kits comprising single stranded oligonucleotides for activating or enhancing expression of a target gene. Methods for modulating expression of a target gene using the single stranded oligonucleotides are also provided. Further aspects of the invention provide methods for selecting a candidate oligonucleotide for activating or enhancing expression of a target gene.