The first two runs ended exactly one year after the mining reward halving.
E.g. December 2016 => Dec. 2017
IMO it will be the same this time, May 2020 => May 2021
So we shall assume the price the BTC will have in May will be the maximum for this cycle?
Should we sell in May?
Yes, even starting from March I think.
April will start the fall. But the falling price will not be less 20K. So if your buying price is less it will not hurt you.