In this study the strong effect of surface density of stabilizers on the outcome of the typical cation replacement reaction in nanoparticles is demonstrated. The density of 2-aminoethanethiol coating determines the growth mode and morphology of the transformation products of CdTe nanoparticles induced by Ag cations. Using quantitative measurements of the stabilizer's surface density, it is demonstrated that CdTe nanoparticles produce Ag2Te nanowire networks upon partial removal of the stabilizer. This process follows the kinetically controlled growth mode but the mechanism changes drastically once stabilizer density is increased. The formation of spherical Ag2Te nanoparticles was observed when CdTe retained the original density of 2-aminoethanethiol. This study provides better understanding of (1) non-classical growth mechanisms of crystals at the nanoscale, (2) effect of stabilizer density on chemical transformations of nanoparticles, and (3) new routes for preparation of nanomaterials.