In general the basic capital gain rate applies (see the previous question). However, if the stock is qualified small business stock (also referred to as Section 1202 stock) and you acquired the shares directly from the corporation for cash, property, and/or services after September 27, 2010, there’s zero capital gains tax; all of the gain is excludable from gross income. Only certain types of C corporations can issue Section 1202 stock, so check with your tax advisor.
The difference between amount realized and adjusted basis on the sale or exchange of capital assets. Long-term capital gains are taxed favorably. Capital losses are deducted first against capital gains, and then again up to $3,000 of other income.