Markets are surging

After a chaotic day that ended with the S&P 500 down 77 points, or 3.9%, markets are now bouncing back fiercely.

Dow futures are up 550 points (3.5%). S&P futures are up 66 points (3.5%). Nasdaq futures are up 172 points (4.3%).

"After vertiginous falls by many equity markets yesterday, and dramatic moves in many currency pairs, with the yen and euro 'winning' while China and commodity-sensitive currencies were beaten up, the 'traditional' Tuesday reaction would be for a bit of a bounce all round," Societe Generale's Kit Juckes said.

But as Juckes also noted, we aren't exactly seeing a uniform bounce.

In fact, China's stock market crashed again. On Tuesday, the Shanghai Composite plummeted 7.6% on Tuesday, which followed an 8.5% crash on Monday.

Following China's market close, the People's Bank of China announced new measures to prop up the markets and economy. China's banking reserve requirement ratio (RRR) was been cut by 0.5 percentage points, which leaves it at 18%, down from 18.5%. It's also cut the one year lending rate by 0.25 percentage points (from 4.85% to 4.6%) and the one year deposit rate by 0.25 percentage points (from 2% to 1.75%).

More to come.