I'm a week into this whole bitcoin thing so be easy on me. I wonder why you would ever sell a BTC ... For example: you buy 100 dollars worth of BTC but the price drops drastically. Why would you sell it when its that low? You KNOW it's going to go up again. You could wait a month (for example), the price will be up again. Or am i totally wrong here?
You are not wrong, but what happens is that there are many people that simply do not have the patience to hold bitcoin they thought that they were going to get big profits in the short term only to realize that they made a miscalculation and that now they need to hold for the long term, and since they are not ready for that they sell for a bad price.