It is, indeed, an important question.

Why sell when prices are going down.

It's counterintuitive, to say the least, to put yourself deeper into the hole when you see things are in red. Although, realize that when you do, you have to be banking on the asset's value to go up at one point in time. The problem some people have is, they tell everyone to hold when they don't know how invested are these people in the industry.

We're all here for different reasons.