Anyone will be tempted when they see that the price of bitcoin can reach the ATH, it could be said that the profit is already in hand and missing this moment is of course something that is difficult to avoid, when the price passes the ATH, which has happened of course the selling pressure is very large, making it difficult for the price to rise higher.
Selling pressure will be very difficult to avoid, especially when investors have seen the profits. I don't deny that some of us have set limits on when to take profits at a certain x, so it will be possible to see them sell when that x is reached. I don't expect the selling pressure to be huge if the hype doesn't die down, it will just make the price break through the next high and hit a new ATH.
Nowadays traders tend to panic because most of them target quick profits. They take advantage of market volatility for short TFs, so the consequence is that selling pressure is always higher when prices move to test resistance.