The U.S. stock market ended last week on a high note after a rocky five-day period following Standard & Poor’s downgrade of the nation’s debt rating. The Dow Jones Industrial Average closed Friday at 11,269, rising 125.71 points in the last day of a period that saw the benchmark move by more than 400 points four consecutive days. Many on Wall Street remain antsy and the DJIA was up another 150 points in the first 15 minutes of trading Monday. “Investors are cautious on bad economic data but also don’t want to lose out on picking up bargains causing these big moves,” said Manal Mehta with Branch Hill Capital. “I think this version simplifies why we have seen such wild moves.” Some of the economic news that keeps riling investors is the high unemployment rate and consumer sentiment and confidence that remain weak. Consumer sentiment plummeted significantly this past month, reaching 2008 recession levels, according to the preliminary Reuters/University of Michigan index report for August. The index score measuring overall consumer sentiment dropped to 54.9 from 63.7 in July. Write to: Kerri Panchuk.