Bond guru Bill Gross, who has long called for the Federal Reserve to raise interest rates, said on Wednesday that U.S. central bankers may have missed their window of opportunity to hike rates earlier this year and doing so now could create “self-inflicted” instability. The Fed seems intent on raising the federal funds rate at its policy meeting this month if only to prove that it can begin the journey to normalization, said Gross, who runs the $1.5 billion Janus Global Unconstrained Bond Fund (JUCAX.O).