Bull points: Flight to quality, no debt, big cash dividend payer. Decent divi yield - 4%. p/e only a v. small premium to market. Pretty defensive in current market environment. If you were a bloody great pension fund and wanting to switch your money from financials where else are the mega-cap safe havens?
I think those are reasons why its done okay recently, not sure I'd short it. Not looked at the chart, but to honest I'm not sure I'd be shorting just because it's gone up for three days...