Difficulty rise, reward halving, mining electricity cost, and profitability decrease may give rise to these situation.
Difficulty rise = means more competition, no miners gonna sell cheap bitcoin so price will pump
Reward halving = Supply will get lower, price will pump
Increase in electricity cost = I think electricity cost are actually decreasing due to more power efficient mining hardware
Profitability decrease = Mining will remain profitable if the miner can have cheap/free electricity and use new improved mining hardware.
All reason you have included seems to be pumping price rather than creating crash.