I don't use Bitcoin only because I am not quite sure how it actually works. I don't plan on using it anytime at all.
Now to answer your question on why it is dropping: 1 word: Trump. He doesn't believe in equal or fair rights let alone equal and fair trades. Last week the stock market dropped because of his foolish policies. They rise because people are buying. The buying of stocks are rose a bit because of people's businesses and buying stock. Bitcoin is the same. If Trump kept his mouth shut the economy, stocks, etc. would be better and more thriving. As long as Trump is in office, Bitcoin and the stock market will decline.