Investors ranging from pension fund Orange County Employees Retirement System in California to money manager William Blair & Co are rethinking their portfolios following Beijing's decision last week to curtail the operations of China's for-profit tutoring industry along with its ongoing campaign to rein in tech companies. The moves fuelled large declines across sectors of China's stock markets and hammered Asia-focused funds stateside, the report said.

The investor retreat sent tutoring firm TAL Education Group's American depositary receipts down some 70 per cent in a matter of days to $6.19 Friday morning. TAL traded above $90 in February. American depositary receipts, or ADRs, are certificates issued to US investors that represent a specified number of shares in a foreign company.

New Oriental Education & Technology Group Inc has fallen roughly 66 per cent since July 22 and was at $2.24 Friday morning.

It was the latest of regulatory crackdowns that have hit the value of Chinese firms as large as Tencent Holdings Ltd, even as US indexes have risen to records. Earlier regulatory moves that had rattled companies such as Alibaba Group Holding Ltd, its unlisted sister company Ant Group Co and Didi Global Inc, which is considering going private again to placate authorities, had already caused concern among western investors.