Shaken by geopolitical shocks, the S&P 500 was flat last week and the Nasdaq nosed just into the red — but the Dow Jones Industrial Average finished significantly lower, weighed down by a double blow from UnitedHealth (UNH-1.96% ) and Nvidia (NVDA+0.54% ) . How Trump’s tariffs could make your iPhone cost $3,500 CC Share Subtitles Off English view video How Trump’s tariffs could make your iPhone cost $3,500 How Trump’s tariffs could make your iPhone cost $3,500 CC Share Subtitles Off English How Trump’s tariffs could make your iPhone cost $3,500 UnitedHealth slashed its full-year forecast after a rough…