Because there is a record that bitcoin hit almost a million when in fact on its early years it just cost like 0.50 dollars its like a negative amount or doesn't have value at all but look at what bitcoin reached now. Although, bitcoin has its highs and lows. it will surely never lose. its either on this year low next 3 years very high. Many of us bitcoin community users or the people who still buying the bitcoin have faith that it will double the price in the future when they avail it right now.