Honestly, Bull run is not my thing anymore, I just want to see Bitcoin price above 15K USD! Bull run not mean Bitcoin at 20K USD like 2017, we have to forget that pump and dump bull run! This year crypto gonna be rock, I feel positive that many big companies will come to the crypto industry and they may open the door for crypto payment! Therefore the most awaiting bitcoin halving is coming! So, overall, the crypto market can see the real bull run this year!
A bull run in Bitcoin that doesn't break the ATH is not a bull run. This may be called a fakeout
A real Bitcoin bull run will take us to 50k if it ever happens. I believe it will because it gains support in the lows year after year and 5 years from now this low will be higher than we are now, which will give us a significant margin to move up. Bitcoin will break ATH or die, I don't think it will ever stabilize so you can expect a bull run like in 2017 somewhere in the future. Not necessarily in 2020.
Any constant continue price change can be called bull run if there's no intervention and even if we will not reach the current ATH made by the past 2017 bull run still we are lucky if we bought bitcoins more cheaper since imagine the total percentage we possibly get if the upcoming halving will bring another historic greatness next year.