Zai Lab (09688) saw its stock price plummet by 5.23% during Friday's trading session, following news of the company entering into a significant guarantee contract. The biopharmaceutical firm's shares took a hit as investors reacted to the announcement of a Maximum Amount Guarantee Contract filed with the SEC on October 13.

According to the SEC filing, Zai Lab has entered into a contract that guarantees RMB300 million (approximately $41.5 million) in working capital loans. This move suggests that the company is securing additional financial resources, potentially to support its operations or ongoing research and development efforts. However, the market's negative reaction indicates that investors may be concerned about the implications of this financial arrangement.

The sharp decline in Zai Lab's stock price reflects investor wariness towards the company taking on additional financial obligations. While the guaranteed working capital loans could provide Zai Lab with necessary liquidity, they also represent increased financial risk. Market participants appear to be reassessing the company's financial position and future prospects in light of this development, leading to the significant sell-off observed in Friday's trading session.