TCO涨，SPG跌？感觉杀价力度不够，还有退四个商场的钥匙，会加剧悲观预期。Simon Property Group SPG,  the largest U.S. retail real-estate investment Trust (REIT) and shopping center operator, recently took similar actions on four of its struggling shopping malls that have $410.9 million of mortgage debt, according to a team at KBRA Credit Profile, a research arm of Kroll Bond Rating Agency.