US stocks fell slightly last week as the prospect of another volley in the trade war between America and China overshadowed a strong jobs report. Investors are likely to look for cover from the tariff battles and political chaos again this week.

Investors are also nervous about seasonal factors: during volatile years, the heaviest sell-offs often come in September and October.

Ryan Detrick, senior market strategist at brokerage LPL Financial, noted that the last time September started out with three straight losses turned out to be inauspicious periods for the stock market - 1987 and 2001.