Just ask Paul Newman. Over the next 20 years, an estimated $84 trillion will change hands in the U.S.; some call this the Great Wealth Transfer, others the Silver Tsunami. This wealth is held in cash and assets, but also in the estimated 2.9 million private U.S. businesses that are owned by those over 55. Many retiring business owners will look to sell their company to private equity or larger conglomerates, while others will pass their businesses on to their heirs.