I really don't know why? I mean will we ever see $800 again... I doubt it for some reason
Bitcoin's price depends on the perception of the people. If enough people consider bitcoin as a good storage of value, it might hype immensely and we will see $800 or even $1000 again in near future. But if they think instead "better live now and spend everything" BTC will go down, too.
When most people have given up on bitcoin, that is when it will start its upward trend.