DM fraction of individual galaxies. Upper panel: dark matter fraction within R_out as a function of stellar mass (M_*), color coded by the circular velocity (V_out) computed at R_out. The horizontal yellow and back dashed lines show the 100% baryon and DM regimes, respectively. The gray shaded area shows the forbidden region. The black arrow indicates that, for a given stellar mass, the fraction of DM in the galaxies increases with increasing circular velocity. The blue arrow shows a shallow decrease in the DM fraction with increasing stellar mass. Lower panel:f_DM(<R_opt) vs. f_DM(<R_out), color coded by stellar mass. The gray shaded area represents the not allowed region (i.e., f_DM(<R_out) ≮ f_DM(<R_opt)). The black dashed line shows the one-to-one relation. For the clarity of the figure (in the lower panel), objects below zero are not shown.