Yes, RBS would boost its share price by performing better. But, since the bank is extremely highly levered (or geared as you folks say). It would not have to perform all that much better to see the stock go from 36 to 70p.
For example suppose a bank is financed with 99 in debt and 1 in equity, so the firm is worth 100. The debt is due in one year. If in one year the bank is worth 101 (a 1% increase), they can pay off the debt and have 2 left over for the stock. So the stock went from 1 to 2, a 100% return (much like RBS needs to do to pay off the CEO). (But note the risk involved, since if the bank's value fell to 99 the shareholders would lose it all, a -100% return.)
Looking at RBS's 2008 balance sheet they have leverage of 41:1 ($41 in debt for every $1 in equity), so my example is only slightly far-fetched.



