https://docs.google.com/spreadsheet/ccc?key=0ArD8rjI3DD1WdGhDN3FBWFptTlZTREN0cFkxZ3JHTncThis spreadsheet is my attempt to fit a logistic function to
the bitcoin price history and thus predict its future.
See Wikipedia
http://en.wikipedia.org/wiki/Logistic_functionBecause the initial phase of the logistic curve is exponential, I
found that a wide variety of maximum bitcoin prices could
reasonably match the price history.
What is interesting is that
the resulting family of curves revealed that the very rapid
growth of bitcoin prices will not last beyond a few more
years.I configured the calculations to accept a guess as to what the
maximum bitcoin price in $US will be. I tried four values from
$40000 to $5000000. For each maximum bitcoin price, I
manually adjusted the starting X value and adoption period so
that the logistic curve passed through the July 7 2010 price and
also passed through the November 11, 2013 price.
The resulting adoption periods range from 10.3 years for
the $40000 max price to 13.6 years for the $5000000 max
price. The logistic function becomes linear at the adoption
halfway point and then becomes exponentially decreasing.
In the case of a $1000000 bitcoin price, the exponential
growth stops in 2017.
Note that the logistic function is fit to the price curve and
models the behavior of speculators, not the underlying bitcoin
economy - which I suppose may take 20-30 years to become
fully adopted, e.g. replace precious metals and fiat currencies.
Likewise, even after full adoption, bitcoin prices will continue
to grow as the underlying bitcoin economy grows.
Here is the logistic price curve supposing that bitcoin reaches a maximum price of $1000000.
The Y axis is the Log 10 of the price.