  We assess the relative strength of solar cycle (SC) 25 with respect to SCs 23
and 24 based on the abundance of halo coronal mass ejections (CMEs). We make
use of the halo CME database
(https://cdaw.gsfc.nasa.gov/CME_list/halo/halo.html) to compare the halo CME
abundance during the first four years in each of SCs 23 to 25. The main result
is that in several aspects such as the abundance, occurrence rate, source
locations, and halo heights, halo CMEs are similar between SCs 24 and 25 but
different from SC 23. This result follows from the fact that weaker cycles have
low heliospheric total pressure, whose backreaction on CMEs allows them to
expand more and hence enhancing the chance of becoming a halo. The solar cycle
variation of halo CME properties is consistent with the precursor-based cycle
prediction methods that indicate SC 25 is similar to or only slightly stronger
than SC 24.
