Official China PMI for May is out at 9 p.m. ET.
Economists polled by Bloomberg are looking for manufacturing PMI to fall to 50, from 50.6 in April.
The HSBC Flash PMI fell to a seven-month low of 49.6 in May.
A reading below 50 indicates contraction.
Ahead of the HSBC Flash PMI report, Deutsche Bank's John Horner wrote that the datapoint was important because a weak number would heighten concerns of a 'broken' Chinese growth dynamic that is no longer responding to rapid credit expansion."
Chinese data has recently disappointed markets. And the main bear argument on China is that it's "taking more and more credit growth in China to deliver less economic growth, according to to CLSA's Christopher Wood. A poor manufacturing PMI number will only bolster that argument.
Here's a look at Chinese PMI and industrial production from 2005 on:
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