It would be long term capital gains, just like if you were selling a stock you had held for more than a year. The rate you pay for capital gains depends on your tax bracket. For someone filing as single the capital gains rates are:

Tax Bracket	|	Capital Gains
10%	|	0%
15%	|	0%
25%	|	15%
28%	|	15%
33%	|	15%
35%	|	15%
39.6%	|	20%