July 10 (UPI) -- The Dow Jones Industrial Average, Nasdaq Composite and S&P 500 each made significant gains on Thursday following the potential of 50% tariffs on copper and Brazilian imports. The Dow closed at 44,458.30 on Wednesday and briefly traded above 44,770 during the afternoon hours, according to MarketWatch . The S&P 500 was up by about 25 points and 0.4% at better than 6,288 during afternoon trading after opening at 6,266.80 and reaching a high of 6,289.04, which is a 52-week high.