Source: Sharecast
As of 1145 BST, Dow Jones futures were down 0.47%, while S&P 500 and Nasdaq-100 futures had the indices opening 0.67% and 0.90% lower, respectively.
The Dow closed 57.35 points lower on Tuesday, taking a bite out of gains recorded in the previous session.
Google parent company Alphabet met expectations with its latest quarterly earnings report after the close but YouTube advertising revenues fell short of estimates, while electric carmaker Tesla's quarterly earnings nearly halved as a 7% year-on-year drop in revenues and price cuts put pressure on profits.
On the macro front, weekly mortgage applications data will be out at 1200 BST, a preliminary reading of June's goods trade balance and wholesale inventories numbers will be out at 1330 BST, preliminary readings of S&P Global's manufacturing and services PMIs were due for1445 BST, and June new home sales figures will be published at 1500 BST.
In the corporate space, AT&T, General Dynamics and Boston Scientific will all report earnings on Wednesday.
Reporting by Iain Gilbert at Sharecast.com