I'm not sure I understand what you're saying, as less than 5% of Goldman shares are owned by insiders. Perhaps you mean to argue that no large-scale businesses should exist in a healthy economy. If so, could you provide an argument?
They are taking a larger and larger portion of overall GDP, while performing a function of dubious value to the society in which they operate (many would say they have negative value). Banks provide a utility to society, or I should so, they should provide a utility, that of liquidity. Their speculation does no good for society, and should not be funded by society, which it is.
