a. price went +20% up, we dont sell.
b. price went -25% down, we sell.
(....)
From what can I see here. It is just showing that a trader doesn't have a goal or plan before entering a trade. I already experienced this like in the scenario I am catching a dump and longing it without planning at all.
In that case, you entered on a trade without stop loss or a price target for that trade, which is really bad practice for a trader.
You are right, just looking at the numbers above, it is enough for us to evaluate the potential of an investor and a trader, a newcomer will always be in such a situation, even some people are stubborn with old concepts, they also often don't know how to sell at the right time and persist with greedy thoughts. Objectives should always be available, from profit to stop loss, chasing a bigger profit and a wrong guess is something many traders do but they didn't know this would bring a bad result