In a state like California, a couple earning $250,000 might be in a 15% federal tax bracket for long-term capital gains in addition to a 9.3% California tax bracket, for a total of 24.3%. Since that couple purchased BTC at $10,000 and then sold it for $30,000 after holding it for more than a year, they would owe a total of $4,860 in taxes on a reported gain of $20,000, leaving them with an after-tax gain of $15,140.