The money tree is in full bloom at Opus Investment Management. The firm manages assets for insurance companies affiliated with parent company The Hanover Insurance Group. It also provides investment management services to other institutional investors, including unaffiliated insurers, foundations, endowments, mutual funds, and retirement or benefit plans. The firm concentrates on fixed-income investments, such as money market instruments, treasury inflation-protected securities (TIPS), corporate paper, and high-yield bonds. Boasting more than $8 billion under management, Opus traces its roots to 1844 when the State Mutual Life Assurance Company was founded.