Shares of Chinese electric-vehicle company Nio Inc. have been volatile on Thursday as Wall Street assesses a recent lawsuit from Singapore’s sovereign wealth fund that revived years-old allegations of fraud.

The wealth fund, GIC Private Limited, filed a

lawsuit in the Southern District of New York in late August naming the carmaker, as well as its Chief Executive William Li and former Chief Financial Officer Steven Feng, as defendants. The allegations center on Nio’s NIO relationship with the “superficially independent” battery-asset company Weineng, which was controlled by Nio.