Real estate developer Vanke’s swirling stock saga has become even more complicated. That came Thursday as Vanke's share price surged with conglomerate China Evergrande Group investing 9.1 billion yuan in the company.

The investment accounts for 25 percent of Evergrande's market cap and secured 4.68 percent of Vanke’s shares. Evergrande now is Vanke’s fourth biggest stockholder, following the Baoneng Group, China Resources Holdings and Anbang Insurance.

Vanke officials say that the frequent changes to the company's share structure have begun to affect its business operations.