S&P UPGRADES RECOMMENDATION ON SHARES OF CITIGROUP TO BUY FROM HOLD(C3.99 **** ) : Based on relative valuation of other larger banks, and given weakness in the markets today, we think C's shares hold value. We are further encouraged by stabilizing credit card default trends. Indeed, C's credit card defaults declined on a sequential monthly basis in July to 10.03% from 10.51%. On a valuation basis, we note that C is trading at only 0.94X our estimate of current tangible book value vs. 1.40X TBV for peers. With capital issues likely behind C, we are raising our target price $1 to $5, a below historical 1.15X our tangible book value estimate.