The list of people challenging eminent domain in Richmond, Calif., continues to grow, as public pension fund, California Public Employees’ Retirement System, joins other banks and investors in its opposition. 

Calpers holds about $11 billion in income-producing mortgage-backed securities and is worried that Richmond's plan will undermine the value of its holdings.

"We are sympathetic to homeowners but as fiduciaries our focus must be in the best interests of our members," Calpers spokesman Joe DeAnda told Reuters in the fund's first public statement on Richmond's plan. "We are watching the issue closely and have some concerns about the precedent this may set and the impact to investors."