Dow and Nasdaq stock index futures briefly turned positive on Tuesday after a number of earnings results, though S&P 500 futures remained slightly lower after China tightened bank lending requirements.

Both DuPont and Travelers Co rose after posting fourth-quarter profits that beat expectations. DuPont added 1.2 percent to $33.20 while Travelers gained 3.8 percent to $50.77. Both companies are Dow components.