IMO - its not so much the money he has, or doesn't have, and how his accountants have played every card available to him, to keep his taxes low or non-existent, I think it may be more about the companies and relationships to companies, and perhaps governments (Is Ra El) that are making him squirm.

If its all legit, then I can only imagine its a privacy concern; if, on the other hand, there is something dubious in his file, its understandable he would fight like hell to keep it quiet until after he leaves office.