The IRS treats bitcoin and other cryptocurrency transactions as property and not as currency. As such, you must figure gain on the transaction in the same way as with any other type of property. The IRS posted guidance (https://www.irs.gov/pub/irs-drop/n-14-21.pdf) on this matter several years ago, but may revisit the topic, so stay alert.
A statutory method of depreciation allowing accelerated rates for most types of property used in business and income-producing activities during the years 1981 through 1986. It has been superseded by the modified accelerated cost recovery system (MACRS) for assets placed in service after 1986.