Stocks are pointing to a lower open on Wednesday as markets prepare for some monthly releases that will indicate further deterioration in the labor market. Half an hour into the session, markets could be pushed higher or lower as Federal Reserve Chairman Ben Bernanke gives testimony to the House Budget Committee on challenges facing the U.S. economy.

At 8:15, the ADP Private Employment report will release its data for May. The report has a mixed record in forecasting the official Nonfarm Payrolls report, which comes out Friday, but it is never ignored by markets and economists often alter their forecasts based on surprise readings.

ADP is expected to report that 510,000 jobs were shed from the economy in May. Such an assessment could be sobering to markets that have riding high recently.

“Note that this report has understated the decline in private-sector nonfarm payrolls by an average of 36,000 per month over the past year,” said analysts at BMO Capital Markets prior to the release. “Still, it’s a good clue for Friday’s payrolls report, and a slower rate of job losses would firm up expectations that the biggest payroll declines are behind us.”

At 10 am, the ISM Non-Manufacturing Index will also be closely watched. The monthly survey for the services, construction, and financial industries is anticipated to report to rise to 45.0, indicating a step forward to stabilization across those sectors. Aside from the headline result, the Employment component plays a key role in forecasting Friday’s official stats.  

Its cousin index, the ISM Manufacturing report, delivered an upside surprise on Monday when New Orders rebounded into growth mode at 51.1. 

Less closely watched will be the 10 am Factory Orders report, which expands upon the Durable Goods report from two weeks ago. The consensus looks for a 1.1% gain for April.