Five popular robo-advisors generated wide-ranging returns for the first eight months of 2016 with portfolios that had a 60/40 mix of stocks and bonds. * Condor Capital rebalanced its Wealthfront account January 15 to maintain a 60/40 portfolio. A hypothetical Wealthfront 60/40 portfolio that was not rebalanced would have gained 6.71 percent during the time period.