The market determines the price; it doesn't necessarily determine the value. I make a distinction between price and value in the following way. During the dot-com bubble, the price of stocks in companies that had no earnings or, in some cases no revenue, was very high. That was based on voluntary purchase and sale of securities in those companies, but the value obviously wasn't that high, and eventually the price fell to the value, and the bubble burst. Just because people are paying a certain price for Bitcoin doesn't mean it is worth that.
On March 19th, 2018. See this statement in context.