Stellar mass as a function of redshift in the COSMOS field. Red dots are principal galaxies (M _⋆  ≥ 10¹¹  M_⊙) with z_phot in the zCOSMOS area, blue dots are companion galaxies (M _⋆  ≥ 10¹⁰  M_⊙) with z_phot in the COSMOS area, and black dots are the red galaxies (NUV − r ⁺  ≥ 3.5) with z_phot in the COSMOS area. We only show a random 15% of the total populations for visualisation purposes. Green squares mark those galaxies in previous populations with a spectroscopic resdhift. The vertical lines mark the lower and upper redshift in our study, while the horizontal ones the mass selection of the principal (solid) and the companion (dashed) samples.