Restframe absolute magnitude LC of SN 2018bbc (binned daily) compared to the literature sample (Sect. 4). SN 2018bbc is shown with a blue line, the fast-rising SNe sare shown with dotted lines, and the other Type Ibn SN LCs are shown with dashed lines. Upper panel: r/R band while lower panel: g/V-band LCs. The LCs are plotted relative to estimated explosion epoch and their respective pre-discovery limits are also shown with triangles. They have been corrected for redshift, MW, and host extinction (where appropriate). The R-band Type Ibn template from Hosseinzadeh et al. (2017) is plotted for comparison, with the phase given since the first available template point.