Toll Brothers, the nation’s biggest luxury builder, reported a second-quarter loss of $93.7 million, as demand for housing weakened in most markets. Though analysts predicted a 96 cent per share drop, Toll Brothers faced a 59 cent per share drop, adding to a 22 cent per share loss earlier this year. “Demand continues to be weak in most markets as our clients worry about selling their existing homes or entering the market before prices stabilize,” Chief Executive Robert Toll said in a statement. The company posted its first quarterly loss in 21 years as a public company in December. Net contracts signed during the quarter, after cancellations, totaled 929 homes, down 44 percent from a year ago.