More encouraging news on trade helped the stock market shake off a weak start and finish higher, the AP reports. It was the fourth straight gain for the S&P 500 index Wednesday, and another record high close. Among the biggest gainers, Amazon rose 3.4% after analysts at Morgan Stanley put out a positive report on the company. Stocks have rallied this week as investors grew more hopeful about trade talks between the US, Mexico and Canada. Canadian Prime Minister Justin Trudeau said that Canada could join a trade pact between the US and Mexico by Friday. The S&P 500 rose 16 points, or 0.6%, to 2,914. The Dow Jones Industrial Average rose 60 points, or 0.2%, to 26,124. The Nasdaq composite increased 79 points, or 1%, to 8,109. (More stock market stories.)