The answer to your question revolves around the treatment of an intangible asset with an indefinite life. Examples of Indefinite -life intangibles are goodwill, trademarks, and perpetual franchises. That is how the company treats its cryptocurrency assets. Such assets are re-evaluated at least annually (quarterly for OBTX). Loss of value is treated as an impairment. An increase would result in a reversal of impairment loss The following link gives a basic explanation of the concepts and accounting...
When an intangible asset’s impairment reverses and value is regained, the increase in value is recorded as a gain on the income statement and reduction to accumulated impairment loss on the balance sheet, up to the amount of impairment loss recorded in prior periods. Increases in value in excess of prior impairment loss is debited directly to the asset and credited to a revaluation reserve account in the equity section of the balance sheet.