Location of the passive candidates observed by ALMA on a SFR-stellar mass diagram, in two redshift bins, based on their sub-millimetre SFR. The arrows represent 1σ upper limits on the SFR. The 1σ error bars on the stellar masses have been conservatively calculated by setting the redshift as a free parameter. The solid lines show the observed MS of Santini et al. (2017). The dotted lines are 1σ above and below the MS (estimated from the observed 0.3 dex scatter), while the dashed line is 3σ below the MS. Individual sources are shown in blue. Robust candidates (i.e. individually confirmed as passive at a 3σ confidence level) have been overplotted in light blue. The large orange symbols show the stacks in bins of stellar mass, denoted by the vertical dotted orange lines.