Yea, as the bitcoin was the main crytocurrency, when other people trade for other crytocurrency, they will still use to buy the bitcoin for transaction purposes.
So from my humble opinion, the price of bitcoin went down because someone try to make use of the low price to scare you and me to sell together and makes the bitcoin lower price.
Then he will buy at a lower price and rebounce back the price to make profit. that was the whole story.