None to date in my opinion. For me to become a weak hands the situation that would trigger me to sell would have to be an almost unrealistic situation, like bitcoin going down to $1,000 in 24 hours or something like that. But that is a scenario that is not going to happen, especially with the bullishness of the coming year. In fact I see the recent dip as a good opportunity to keep accumulating. The fools who are selling will regret it.
You dont have to call them fools though. Not everyone you see thats holding bitcoin has a strong heart to hold on for a longer time after bitcoin had reached $100K already in this bull run, theyll immediately rush to sell their holdings off since they even already made profit from what theyve invested initially.
Bitcoin holders differs and some may never regret selling their bitcoins now because that was what they planned for, the profits target and they were able to achieve it, so they wont feel regret but rather wait for another dip to buy. Seeing how the market is transgressing will even make them feel scared for those who dont have the strong heart to hold on to the market volatile nature.
It is very unrealistic that bitcoin will fall back behind or to $1,000; if it does so for example, I bet you we will not have more bitcoin holders again as many would have even sold off before it gets to that price within that period.