The average return on the stocks is negative for the week and month after geopolitical conflicts. The economic risk is higher oil prices, a headwind to global growth.

U.S. crude oil futures rallied more than 6 percent to peak at $78 a barrel, more than $1 higher than the price on Jan. 20 when Trump was inaugurated. That jump is likely to filter through to gasoline prices just as drivers prepare to hit the road for the long July 4 weekend next week.