For Bill Gross, quitting Pimco’s $222 billion Total Return Fund to take over a $13 million fund at Janus Capital is like resigning the U.S. Gross stunned the investing world on Friday with his abrupt departure from Pimco, the $2 trillion asset manager he co-founded in 1971 and where he had run the Total Return Fund, the world’s biggest bond fund, for more than 27 years. Come Monday morning, Gross will join Denver-based Janus and next month will take over its Unconstrained Bond Fund, which was only organized in May. Janus is an asset management firm once known for picking hot Internet stocks.