Alibaba (BABA) dropped 10.7%, the steepest decline since its listing in the city in November 2019. The fall in Hong Kong followed a similar plunge Thursday in its share price on Wall Street after the company reported disappointing quarterly earnings and warned that results for the year will miss analysts' estimates.

So far this year, Alibaba's stock has dropped 40%, wiping about $234 billion from the value of the company. Friday's plunge dragged down Hong Kong's benchmark Hang Seng Index (HSI), which fell 1.1%.

Alibaba's sales grew 29% last quarter from a year ago, to $31.1 billion. Wall Street was expecting revenue of $32.1 billion. Earnings per share fell 38% from a year ago and were below expectations. The company said that sales for its current fiscal year should rise between 20% and 23% from a year ago. Analysts were predicting growth of nearly 28%.

Alibaba and fellow Chinese tech giants Tencent (TCEHY), Baidu (BIDU) and TikTok owner ByteDance have been subject to increased regulatory scrutiny from the Chinese government in the past year.

Last November, Beijing yanked the IPO for Alibaba's Ant Group affiliate, which owns payment app giant Alipay. In the year that followed, the Chinese government's regulatory might has changed industries ranging from tech and finance to gaming, entertainment and private education.

In April, regulators slapped a record $2.8 billion fine on Alibaba, accusing it of behaving like a monopoly. Meituan, Tencent, Pinduoduo (PDD), and other tech firms have also been investigated or fined over alleged anti-competitive behavior.

In its earnings release on Thursday, Alibaba cited a "regulatory environment that affect Alibaba's business operations" and "privacy and data protection regulations and concerns" as some of the uncertainties it was facing.

Alibaba's giant cloud business continues to post impressive results though. Revenue rose 33% from a year ago for that unit. Alibaba Cloud has helped the company expand beyond China as well.

"Alibaba continued to firmly invest into our three strategic pillars of domestic consumption, globalization, and cloud computing to establish solid foundations for our long-term goal of sustainable growth in the future," Alibaba chairman and CEO Daniel Zhang said in a statement.

"Amid an unprecedented year following tightened regulation, without much flexibility, [Alibaba] will need to navigate through the multiple headwinds while continuing to invest in technology innovation, globalization and expand its domestic consumer reach," Citi analysts said in a research report on Friday.

Alibaba's results come one week after the company wrapped up its annual Singles Day online shopping extravaganza. Chinese consumers continued to shop for bargains during the event, but sales growth for the platform was slower than last year.

Part of that may be because of the regulatory environment, but Alibaba is also facing tougher competition as well as a slowdown in the Chinese economy.

During a conference call with analysts Thursday, Zhang said "economic headwinds, coupled by intensifying market competition also affected our core commerce business in China."

He noted that there was a slowdown in apparel and general merchandise but that consumer electronics and furniture demand remained resilient.

Rival JD.com (JD) also reported earnings Thursday. Sales and profits topped forecasts, and the company's shares closed up 6% in New York.

On Friday in Hong Kong, JD.com's shares rose more than 9%.

"Consumers and business partners increasingly trust and rely on JD, and we were able to outpace the industry growth in China in the third quarter," JD.com president Lei Xu said in the earnings release.

JD.com's Hong Kong-listed stock has surged more than 20% in the past six months, while Alibaba shares have fallen more than 30% during the same time frame.