Kong listing hopefuls are shedding light on the inner workings of their initial public offerings, revealing cross-investments and personal connections, just as regulators step up scrutiny of structures that risk distorting the market.

The unusual level of detail was on display Friday in the prospectus of Hosin Electronics Co., a Chinese memory product maker seeking to raise HK$1.22 billion ($156 million) in an IPO. The company disclosed that a circle of corporate allies and personal acquaintances are among its cornerstone investors — which receive guaranteed allocations in exchange for agreeing to hold the stock for a certain period — who agreed to absorb as much as 42% of the offering.

The Hosin backers include smartphone maker Shenzhen Transsion Holdings Co. and chip supplier Shenzhen Longsys Electronics Co. Hosin disclosed that it had also served as a cornerstone backer for both companies’ own Hong Kong listings this year. While Hosin stated that the deals weren’t “inter-conditional,” the dynamic illustrates how industry partners at times become involved in each other’s deals. Hosin’s filing also details how it was introduced to other wealthy investors through acquaintances and industry meetups.

The additional disclosures are among the first since Hong Kong regulators started ramping up scrutiny of the city’s booming IPO market to boost transparency and improve the quality of listings. In mid-October, they asked IPO banks to look more closely into potential connections between investors and listing applicants, and to avoid arrangements that could paint an inaccurate picture of buyer demand.

There’s no indication of anything untoward in the type of cross-investment detailed in the Friday filings. Business partners and close allies have long been part of the Hong Kong IPO scene, and there have been similar cases where companies invested in each other’s listings. Hosin and Longsys are strategic partners and both are suppliers to Transsion, their filings show. What’s new are the specific disclosures that highlight those relationships more explicitly.

The pattern that emerged in Hosin’s case shows a set of companies that have all invested in each other. Along with Transsion and Longsys, the three companies were cornerstones in each other’s offerings, their filings show. Transsion has also been active elsewhere,g up as a pre-IPO shareholder of audio chip company Shanghai FourSemi Semiconductor Co., and backing a fund that was a cornerstone investor in the IPO of diaper brand Softcare Ltd.

Hosin’s offering documents Friday also lay out how the company became connected with wealthy individual investors in more detail than usual. Former venture capital executive Chen Chun-Cheng and tech industry investor Yeh Pei-Chen both agreed to buy stock after being introduced by an unnamed “mutual acquaintance,” the prospectus shows, without specifying if the same person made both connections.

Liu Ling, a businesswoman who trades electronic components, committed to invest after being introduced by a unspecified member of management, according to the prospectus. Chen Li-Shun, a director at private equity firm MagiCapital, is participating after meeting the company “through an annual investor event.”Another cornerstone investor, W&W Capital Ltd., is part of the same corporate group as an existing Hosin shareholder.

A spokesperson for Hong Kong’s Securities and Futures Commission said the regulator doesn’t comment on individual cases. The spokesperson pointed to an Oct. 13 circular, which detailed the responsibility of IPO banks to conduct robust due diligence and “proactively advise” listing applicants on their disclosure obligations.

The SFC urged sponsor banks to “critically assess the commercial substance of transactions, relevant fund flows and investor relationships.”Leaders of the banking syndicates should also inquire about the relationships between a listing applicant and investors, and their implications for the genuineness of investor demand, the SFC said in the October circular.

Other IPOs that launched Friday also detail existing connections between the companies and their cornerstone investors.

Chinese chip assembly firm Jiangsu Xinde Semiconductor Technology Co. lined up three cornerstone buyers that are collectively taking up about a third of its $130 million offering. The company highlighted that one of them is Suzhou Maxwell Technologies Co., a maker of manufacturing equipment that it said is also one of its suppliers. The prospectus says the cornerstone investment and the companies’ commercial relationship aren’t dependent on each other.

Representatives for Hosin, Longsys and Transsion didn’t immediately respond to requests for comment.

“HKEX is committed to upholding the quality and integrity of Hong Kong’s markets and maintaining high standards of transparency,” the bourse operator said in an emailed statement, declining to comment on specific companies. “Generally speaking, we require the listing applicant to disclose all material information to enable investors to make a properly informed assessment.”Xinde Semiconductor said in a statement that it maintains an independent supply chain that’s not overly reliant on any single vendor. Some of its packaging lines are compatible with Maxwell equipment, and the two companies’ technical road maps are “broadly aligned,” Xinde Semiconductor said, adding that the cornerstone investment and related commercial arrangements aren’t inter-conditional. Maxwell didn’t immediately respond to queries.