Global investors have been paying more and more attention to Evergrande, the sprawling Chinese real estate business on the brink. They're increasingly worried about what they see.  What's happening: Stocks in Europe tumbled Monday morning after Hong Kong's Hang Seng dropped 3.3%, suffering its worst decline in nearly two months. Chinese banks, insurers and other real estate companies were slammed. US futures are also sharply lower.  Shares of Evergrande Group plummeted 10% in Hong Kong, hitting just 2.28 Hong Kong dollars ($0.29) per share. The stock has shed 84% so ...