No, only the gain is income, the value of the stock is not. In your example you would need your stock to have gained 350k and to sell it all. You could sell 349

No, only the gain is income, the value of the stock is not. In your example you would need your stock to have gained 350k and to sell it all. You could sell 349k this year and pay nothing, and 1k next year and pay nothing.