US stock futures close mixed Tuesday: Dow down 0.34%, Nasdaq 100 down 0.33%

The near-flat S&P against declines in the Dow, Nasdaq 100 and Russell 2000 points to a session where weakness was broad but shallow, with no single segment driving the move. The Russell 2000's position as the weakest of the four is the detail worth noting, since small caps are typically the most domestically sensitive and their underperformance can signal caution about the domestic outlook. Whether that small-cap lag persists or reverses in the next session is the open question.