Listings of apartments for sale displayed at a real estate office in Shanghai, China, on Monday, Aug. 30, 2021. Qilai Shen | Bloomberg | Getty Images BEIJING — Wild swings in Chinese real estate stocks and bonds are keeping investors on edge — these news headlines could cause troubles in the sector to spill into the rest of the economy, says S&P Global Ratings. While the plunge in Evergrande’s shares has abated, the volatility in other Chinese real estate companies has continued this month. On Thursday, Kaisa shares briefly popped 20{d4d1dfc03659490934346f23c59135b993ced5bc8cc26281e129c43fe68630c9} after news it could stave off default. On the same day, a Shanghai-traded bond from developer Shimao plunged 30{d4d1dfc03659490934346f23c59135b993ced5bc8cc26281e129c43fe68630c9},…