BOSTON -- Wall Street firms encourage the top brass to own equity in order to align their interests with those of ordinary stockholders. It's good to know the system works -- even if, so far, the main result is the satisfaction of knowing that the big shots are feeling your pain.Take Citigroup ( C), where board members and senior management are losing big money as the bank's deepening crisis sends its shares into freefall. Their total losses on stock and options this year? Nearly half a billion dollars. That's right. Thirty board members and top executives have seen nearly $500 million wiped off the value of their shares and options. Even for Citigroup's well-heeled head honchos, this is a lot of dough. And it shows that anyone who believes the wealthy can be wholly insulated from the knock-on effects of the subprime meltdown is dreaming. The news comes at fears of writedowns and mounting losses sent the stock plummeting to a fresh four-year low. The figures on personal losses at the top of the bank come from an analysis of Citigroup's public filings. They include a $52 million loss suffered just by Mr. Establishment himself -- executive committee chairman Bob Rubin, Bill Clinton's former Treasury Secretary and a leading figure in the Democratic Party.