The possibility of nuclear war in Asia is having a depressing effect on stock markets. Look at this chart:
Metals and commodities are outperforming the S&P 500 in August. Precious metals are considered a 'safe haven' for investors in times of turmoil. Their flight to safety is reflected in the chart. Worries over whether the extreme right will attempt another government shutdown to ransom their deluded demand to build an ineffectual wall against Mexican immigrants are creating a perception of increased risk. Add to that an overvalued stock market, and a President who is unable to govern with consensus.