Key TakeawaysThe S&P 500 gained 1% on Monday, Aug. 19, securing its eighth straight winning session ahead of this week's Jackson Hole Economic Symposium.AMD shares moved higher after the chipmaker said it would acquire server manufacturer ZT Systems.Shares of printer and PC maker HP lost ground following a downgrade by analysts at Morgan Stanley, who cited limited upside potential. Major U.S. equities indexes moved higher to open a new trading week. Over the next few days, investors will likely scrutinize c ...