U.S. stock index futures dipped on Wednesday, following a tech-led selloff on Wall Street, as investors parsed earnings from retailers Target and Lowe's for clues on consumer spending ahead of a key Federal Reserve symposium later this week.

The blue-chip Dow opened higher on Tuesday, aided by a rise in shares of Home Depot after the retailer kept its annual forecasts intact, while caution dominated the overall mood ahead of a key Federal Reserve conference scheduled later in the week.