It depends on your jurisdiction, your filing status, the amounts in question and other details. You might have more success asking on
the Legal board. That's where most tax discussion takes place.
In most jurisdictions, you'll owe capital gains taxes on any trading/investment profits. For example: If you buy 1BTC at $1,000 and sell at $10,000 that's $9,000 in capital gains. That gets multiplied by your capital gains tax rate to determine your tax liability.