By MATT OTT SILVER SPRING, Md. (AP) — The seemingly unstoppable rise of Bitcoin continued Tuesday with the cost of a single unit of the digital currency rising above $50,000 for the first time. The same Bitcoin just one year ago would have cost you $10,000. The price is up almost 200% in the last three months alone. It rose sharply early Tuesday and while giving up some of those gains, continues to