While it can and does inflate. There is a reasonable calculation at the rate of inflation(e.g. they know approximately how many new coins will be mined per year

While it can and does inflate. There is a reasonable calculation at the rate of inflation(e.g. they know approximately how many new coins will be mined per year) So its priced on. And a lot of the spike and gains have been on too short of a time scale to be effected by it.