Multi-wavelength light curve for Mrk 501 during the highest X-ray activity measured with Swift/XRT to date. The correspondence between the instruments and the measured quantities is given in the legends. The horizontal dashed lines in the VHE light curves depict the flux of the Crab nebula reported in Aleksić et al. (2016b). For BAT, the daily fluxes were computed using the spectral shape from the time interval MJD 56854.5–MJD 56872.5 (see Sect. 2.4.1).