Its just a prediction based on the old data. I always refer coinmarketcap.com to refer the old data and ratio. I would say, bitcoin value would boom upto minimum $45K this December 2018 end. If you look at January 2017's bitcoin value, it was at $1000 and in December 2017 it was $21000. Just look at 2018 January's value. it was at $9000. So calculating the data, the value wo uld start increasing from July with bit raise in April.