The deal is another step toward $10 billion in assets but the CEO sees it growing much larger. : A fast-growing, private equity-backed registered investment advisor in Minnesota made another deal this week. Wealth Enhancement Group, a Minneapolis-based RIA that oversees $9.3 billion, has acquired OneSource Retirement Advisors, a Philadelphia-based RIA with $276 million in client assets. Terms of the deal were not disclosed and it is expected to close in November. The acquisition is Wealth Enhancement Group’s eighth in the last five years.