Wall Street drifted modestly lower before the opening bell as uncertainty over global trade seeps into the busiest week of earnings this quarter from major corporations, as well as a raft of economic indicators Futures for the S&P 500 dropped 0.

U.S. stocks are drifting at the start of a week with many potential flashpoints for markets including earnings reports and economic data

The moves come after each of the three major averages saw a third weekly decline in the last four trading weeks.