Doesn't he have a permanent profit share in the Bain funds? Bain is one of the more successful private equity funds in the world, and as such, I'd think that 'stake' could easily be valued at 10-20x earnings.

In case anyone doesn't know what you're talking about:

http://www.gao.gov/products/GAO-15-16

A small number of taxpayers has accumulated larger IRA balances, likely by investing in assets unavailable to most investors—initially valued very low and offering disproportionately high potential investment returns if successful. Individuals who invest in these assets using certain types of IRAs can escape taxation on investment gains. For example, founders of companies who use IRAs to invest in nonpublicly traded shares of their newly formed companies can realize many millions of dollars in tax-favored gains on their investment if the company is successful. With no total limit on IRA accumulations, the government forgoes millions in tax revenue. The accumulation of these large IRA balances by a small number of investors stands in contrast to Congress's aim to prevent the tax-favored accumulation of balances exceeding what is needed for retirement.