Alibaba (BABA), the Chinese e-commerce giant, snatched up nearly 33 million shares of the daily deals site Groupon (GRPN), the company disclosed in a regulatory filing on Friday.

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The stock purchase amounted to more than $100 million. Alibaba’s recently disclosed 5.6% stake makes it the company’s fourth largest shareholder as of the end of last year, Bloomberg reports.

A spokesperson for Alibaba described the strategy of taking positions in international firms as a common practice for the company. “We bought a very small minority stake in Groupon in order to share ideas between U.S. and China markets,” he said, mentioning in particular the online-to-offline deals business. “This is a passive holding and if Groupon management would like to exchange experiences with us, we are prepared to share.”

Alibaba has taken similar positions in other companies, including the online retailer Jet.com, the augmented reality startup Magic Leap, and the ride hailing service Lyft, Bloomberg reports.

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Groupon did not immediately reply to Fortune’s request for comment. A spokesperson did tell Bloomberg, however, that the company was unaware of the stake until the filing. “Alibaba has a reputation as a long-term holder, and we’re pleased that they take the same view of Groupon’s opportunity and execution as we do,” he said.

Groupon, once an e-commerce darling that experienced rocketship customer growth, has floundered for years following a shoddy public market debut in 2011. (Fortune’s Dan Primack and Erin Griffith have argued that the company is a success and a flop, respectively.)

Groupon shares are up nearly 80% since the news became public.