Buying activity rebounded after slipping in August, indicating that demand for housing continues despite a series of recent economic hits: stock market declines, a slowdown in China, struggles in emerging nations such as Brazil and Turkey, and stagnation in Europe. The real estate market appears to have reached a stable plateau in recent months, aided by mortgage rates near historic lows and steady job gains. A recent survey shows that 20 percent of millennials say they need financial help from their parents to buy a home, compared to just 8 percent of the older baby boomer generation who needed parental assistance, according to the finance company Credit Karma.