BTC was recognized by U.S. government. It means that U.S. are ready to wide adoption of crypto and they open their market for new opportunities. When it will become clear that BTC is very profitable payment method, price may grow.
In 2018, the price has been unstable and went below 10k figure that was a big decline in value and we were expecting a different market but something happened opposite to our expectations. The main reason for this decline is due to the major market factor that is the demand rate factor so whenever we see any decline in price the major thing we notice is a decrease in market demand.