The Nasdaq Golden Dragon China Index, which follows the 98 biggest US-listed Chinese stocks, has fallen by almost 15% in the last two trading sessions.
The index has now plummeted by more than 45% since hitting a record high in February.
The slump comes after a series of crackdowns by Beijing on its technology and education industries.
This has led to around $770bn (£556bn) being wiped off the value of US-listed Chinese stocks in the last five months alone.
The latest blow came as Beijing unveiled a massive overhaul of China’s $120bn private tutoring sector, under which all institutions offering tuition on school curricula will be registered as non-profit organisations.
That pushed down the stock market value of private education firms in the US, Hong Kong and mainland China.
Chinese authorities are also cracking down on a wide range of online services from food delivery apps to music streaming platforms.
On Monday, China’s State Administration for Market Regulation (SAMR) issued new rules aimed at improving the employment conditions of delivery workers.
The SAMR called for delivery workers to be paid at least the minimum wage, have their workload eased, and be given better training.
Meituan, which runs one of China’s biggest food delivery apps, saw its shares lose a record 17.6% on Tuesday in Hong Kong trade, on top of a 14% slide the previous day.
Regulators said the move was aimed at tackling the company’s dominance of online music streaming in the country.
And earlier this year, Chinese e-commerce giant Alibaba accepted a record $2.8bn fine after an official investigation found that it had abused its market position for years.