Continued slowdown in economic activity in China triggered fresh round of selloffs in global equity markets, which has already remained quite fragile given recent selloffs and possibility of rate hikes from US Federal Reserve as early as September.

China's official manufacturing PMI, which sometimes is not considered as true presenter of weakness in the economy and overestimating economic strength dropped below 50 to 49.7, lowest level since 2012.

While this has been enough to spook investors, private reading showed weakness in services sector too.

While official non-manufacturing PMI stayed well above 50 at 53.4 (compared to prior 53.9), private reading showed considerable slowdown in services sector, with PMI dropping to 51.5, well below market expectation of 53.9.

This slowdown was enough to spook investors and begin fresh round of equity sell off, which might exacerbate further once New York opens for business.