Wall Street: Futures tumble on growth worries, Chinese tech rout

US stock index futures fell more than 1 per cent on Thursday as the growing spread of the Covid-19 Delta variant cast doubts over an economic recovery, while a rout in Chinese technology stocks appeared to have spilled over.

Atlanta Federal Reserve President Raphael Bostic warned that a spike in the highly infectious variant could hamper a US economic recovery.

Minutes of the Federal Reserve's June meeting also showed that officials felt that an economic recovery still had a long way to go.

US-listed Chinese stocks tumbled in premarket trading, tracking steep losses in China and Hong Kong as investors feared more strict measures from Beijing on the technology sector.

E-commerce giant Alibaba Group fell 2.6 per cent, while internet search engine Baidu shed 3.8 per cent.

Didi Global, whose app takedown by the Chinese government had sparked a recent selloff, fell 6.5 per cent, while FAANG group of companies dropped between 0.9 per cent to 1.7 per cent.

The CBOE Volatility index, Wall Street's fear gauge, jumped 3.1 points to its highest level in over two weeks.

At 5:50 a.m. ET, Dow e-minis were down 367 points, or 1.06 per cent. S&P 500 e-minis were down 43.75 points, or 1.01 per cent and Nasdaq 100 e-minis were down 156.5 points, or 1.06 per cent.