For years, big banks have delivered nearly all of their conforming mortgage production to the government-sponsored enterprises and retained their jumbo mortgages in portfolio. But some big banks have changed tactics, exploring differing execution options for their originations. Paul Donofrio, CFO of Bank of America, said the bank retained about 90.0 percent of its mortgage production on balance sheet in the second quarter of 2017. BofA had $18.0 billion in originations during the quarter, including first mortgages and home-equity loans. The loans retained...