While home price gains across the U.S. are fairly sustainable, some metropolitan areas where jumbo loan underwriting standards are considered relatively loose may be on the cusp of a potential bubble, according to Fitch Ratings. The San Francisco market, where home prices climbed to record levels in the third quarter of 2015, now looks like it did during the dot-com boom of the late 90’s, Fitch said. The firm’s recent RMBS Sustainable Home Price Report noted that homes in the Bay Area have climbed 62 percent above their post-recession low in early 2012 and are up 10 percent in the past year. At current levels, the Bay Area market is...