A key stock market index in Hong Kong saw the biggest single-day drop since the financial crisis on Tuesday. The Hang Seng index fell by -2172.99 (-9.41 percent) on Tuesday. The drop followed an announcement on Tuesday by China's economic planning agency that outlined details of measures aimed at boosting the economy but refrained from major spending initiatives.

Investors in Hong Kong have bet a record amount on exchange-traded funds that profit when stocks decline, showing how quickly sentiment is shifting following a breakneck rally.

Wall Street held firm even though stock markets around the world sank after scary swings in China, as euphoria about possible stimulus for the world’s second-largest economy gave way to disappointment. Stocks tumbled 9.4% in Hong Kong, marking their worst day since the 2008 global financial crisis.

The group of tech stocks known as the Magnificent Seven all rose on Tuesday, with the largest gain going to Nvidia, up 4.1%.

U.S. stocks are steadying themselves on Tuesday as falling oil prices release some of the pressure that’s built up on the market. The S&P 500 was 0.8% higher in afternoon trading and clawing back most of its loss from the day before.

Oil prices sank and global stock markets diverged on Tuesday, with Hong Kong suffering its worst day in 16 years as China held off announcing fresh measures to boost its