Bitcoin price modeling strategy:

1) find regression line of log(price) vs. Log(time)

2) find biggest outlying data point and delete it

3) re-run linear regression and go to step 2 until half of all data points are deleted

4) divide the deleted data points into two groups: higher than and lower than regression line above

5) for each group, plot the price minus the regression line price prediction and try to parameterize this new graph.