(Bloomberg) -- Chinese tech shares fell near a record low in Hong Kong, as Didi Global Inc.’s U.S. delisting announcement and rising scrutiny on mainland firms listed there dealt a further blow to already soured sentiment on the sector.

The Hang Seng Tech Index, which tracks mostly big Chinese technology giants traded in Hong Kong, dropped as much as 2.2% to hover over its lowest level since the gauge was launched in July last year. Members of the index have seen about $1.5 trillion of combined market value evaporate since a February peak. 

NetEase Inc. and Bilibili Inc. were among the top losers. The declines followed the Nasdaq Golden Dragon China Index’s drop to the lowest in almost 19 months in the U.S. 

Ride hailing giant Didi has begun preparations to withdraw from U.S. stock exchanges and will start work on a Hong Kong share sale, it said in a statement Thursday, a stunning reversal as it yields to demands from Chinese regulators that had opposed its American listing. 

Separately, the Securities and Exchange Commission on Thursday announced its final plan for putting in place a new law that mandates foreign companies open their books to U.S. scrutiny or risk being kicked off the New York Stock Exchange and Nasdaq within three years. It came after SEC chairman said in July that the agency required more information for Chinese firms seeking listings in the U.S. 

The moves added to woes faced by Chinese tech companies that have already been grappling with Beijing’s tightened regulations on areas ranging from digital finance and data security to online games and overseas listings. 

A delisting from the U.S. stock market could raise the Chinese firms’ cost of capital, according to a Bank of America report last month. There are more than 270 Chinese ADRs traded in the U.S. with a combined market capitalization of $1.8 trillion, and over 150 of them do not qualify to list in Hong Kong, the report said. 

The Hang Seng Tech Index has lost about 45% since a February peak, with declines accelerating in recent weeks after disappointing earnings season and a report that China plans to ban companies from going public on foreign stock markets through variable interest entities.

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