Next year is first possible for a bull run. More likely 2022. But of course there can be short bull runs like happened in Q2 of 2019 or in January and February of this year. Price increase drastically in those times but It dont last long enough to breach old ATH.
Short or big but you can expect a bull run to be happening within this year because history needs to be repeated even for bitcoin markets. After halving, as per the tradition of bitcoin markets, we must need to have bitcoin prices around it ATH by this year end. So far bitcoin is doing great regardless of whatever economic situation is going on worldwide. So, I believe this trend will continue hence bitcoin will not be having any problem to perform as per exactly its history.