It's my first year to rely on cash savings and stock sales for income. Now I plan to sell some stock, which would generated large long term gains. Because my stock broker does not do withholding for those sales, how can avoid under-withholding penalties? To my understanding, the estimated tax for should be four even payments. Is it unavoidable that an unplanned large capital gain close to the end of year will cause penalty? How is the penalty calculated? I am in CA. Are the Fed and CA estimate tax rules and penalty calculation similar?
