This paper revisits the valuation of cumulative preferred stock, whose fair price is shown to critically depend on dividend arrears and the firm's earnings. Such fair price is an almost everywhere concave function of the firm's assets value and it tends to increase in the rate at which the firm generates earnings. When dividends are in arrears, the preferred stock call price should increase accordingly. If not, cumulative preferred stock becomes similar to the non-cumulative one. The value of a low credit quality preferred stock may well increase with interest rates. A finite difference algorithm is presented to value preferred stock as a function of the firm's asset, stochastic interest rates and dividend arrear