A stock on its way to hell, such as this one, will always be difficult to short, since no one who trades Citi has much doubt about where it’s ultimately headed. It is this brash certitude that makes the short-squeezes too vicious to trade, the more measured rallies too anemic. The last such thrust failed by 23 cents to reach a midpoint resistance we’d spied at 19.48, and even in retrospect it is difficult to see how we might have caught the top. If and when we do, though, it will be by way of legging on a calendar put spread well below the market. Trading concerns aside, Citi will remain not only a financial bellwether, but a telltale for the banking system as a whole. When Citi shares are rising, we can assume that denial among investors is rising; and when the stock is falling, it is fear that rules. Citi cannot tell a lie, and right now it is saying we ought not put much store in the latest good news from Paulson, Bernanke et al.