Yeah, you pay tax on the $10 since it's profit.
Or, you can wait for Jack to launch his btc loan service, where you put btc as collateral in exchange for fiat and you don't have to pay taxes on loans. Then just roll over the loan with a second loan, which liberates the btc in your first loan. Rinse and repeat. This is not financial advice, and keep an eye on the LTV ratio.