In a retirement account if you sell stock and are under the age of 59 1/2, you only pay tax if you withdraw the money. If you were to sell say 5% of your SFOR shares at 50 cents per share and obtain say $5,000 - you could reinvest that money into something and pay no tax. If you take an early withdrawal, you are subject to a 10% tax penalty in addition to your regular tax rate. At least that is my understanding and I know that is right about accurate if not 100% accurate.