What is your views and conditions at that time?
everyone will surely regret it if they have gone through times of altcoin bulls reaching new ATH and has been followed by a correction. because the new ATH is unlikely to happen in the near future, but it takes a long time. and if we can sell altcoins on new ATH then we have a chance to get bigger profits. and we can buy it back when the correction occurs.
The closest example is when the bull market occurred in 2021, some coins managed to reach the new ATH price and I am one of those who
regret not selling the coins I have when the price reaches new ATH. Even though if I manage to sell it at the new ATH price, I will get a big profit,
I also had the opportunity to buy again in the current bear market. Therefore I learned from my mistakes that it is still difficult to control the greed
that is in me, this is what finally missed my opportunity to be able to sell at the new ATH price. Now I have to be patient waiting for the market
to be bullish again, because as you said new ATH probably will not be achieved in the near future. So besides I have to be patient holding the coins
I have, I also have to start accumulating very potential coins. So when the bull market came I was ready to sell the coins I had at the new ATH price.