At $19000, there are a lot of people who are in profit like 1.5x, 2x or even more considering they have purchased at the dip last year (or this year, cannot remember when it happened around $4000). So, I think most of them have liquidated their money as BTC was stable for a few days and they had speculated no ATH this time too. This is what I think.
Great to see a mate from 2011.
If I bought bitcoin at $4k, I will sell at $19,5k as well, considering the ATH is $20k, so people expected the hardest resistance to breaking is $19,5k.
It's purely 'buy and sell', investors and traders taking profit whenever bitcoin hit a certain price.
However, it's not the peak yet, as bitcoin slowly recover above $17k, bitcoin still be able to reach a higher point than $20k by the end of this year, mid-December probably be the highest price.