well if you look at the gold bubble. the first bubble went from 1970 to 2000. (20 years) bitcoin since the early 2013 peak until the low of now (2015) is very similar to gold's first 30 years. after 2000, the gold bubble ended and hit its low. then it blasted off and bubbled again. this time it reached its previous ATH within 11 years (2011). if bitcoin were to follow a similar path...that would equate to surpassing its ATH in november 2015...similar to what you're showing in your chart.