Depends if you are selling for a gain or loss. Nothing will be due when you sell for tax. There are no penalties in taxable accounts. If selling for a gain, you will either have long term or short term capital gains tax due. If selling at a loss, there is no tax due and you can claim up to 3000 in a tax deduction, net of offsetting gains.

Just withdrawing cash from the account is not a taxable event.