I know its an individual thing, but if you are in an alt and it is pumping...when is the best time to sell?
Depends on the market situation and what type of your trading. For example, I am a daily trader. If the market is in the uptrend, I will sell my altcoins if the price can increase 50% - 80%. But if the market is in a downtrend like in the current days, I mostly take profits once the price can increase 20% - 30%. I won't set a too high target for taking profits because I know it is difficult. Well, it is my own strategy, other traders may be different.
It's true that such a strategy is very suitable for day traders like you,
but again traders have their respective strategies depending on what they want to achieve,
What is clear is that to know when is the right time to sell we need to monitor market movements because otherwise we can lose the moment