That lower "book" value captures a loss that the government has already absorbed on the investment: theloss is the difference between what the government paid for theshares and themarket price of RBS on the days the then Chancellor, Alistair Darling, actually handed over the money for theshares.
At the same time the stock seemed like a good buy partly because its shares seemed to be oversold, driven down by the prospect of increasing competition, a slight loss in market share and a Securities and Exchange Commission inquiry into revenue recognition errors.