Vancouver and London topped a list of cities most at risk of a housing bubble, according to UBS Group’s Bubble Index, which charts the housing markets in 18 major cities. New York’s housing market, on the other hand, was ranked in the “fairly valued” category, grouped with Boston and Singapore. The most overvalued housing market in the U.S. according to UBS, is in San Francisco, where real prices have increased by more than 50 percent … [more]