When calculating this value, Jameson came up with one key assumption, which is the value of Bitcoin would increase by 0.42% on a daily basis.

While I agree that guesstimating the future price of Bitcoin should use exponential numbers, 2017 could easily prove to be an outlier so something like 0.2% might be more reasonable. But even doing that, the price target for 2020 ends up at about $20,000.

Even using a very conservative 0.1%, we'd end up at over $7500.