A cloud of gloom hovered over the International Monetary Fund's annual meeting this month. With the global economy experiencing a synchronized slowdown, any number of tail risks could bring on an outright recession. Among other things, investors and economic policymakers must worry about a renewed escalation in the Sino-American trade and technology war. A military conflict between the United States and Iran would be felt globally. The same could be true of "hard" Brexit by the United Kingdom or a collision between the IMF and Argentina's incoming Peronist government.

Still, some of these risks could become less likely over time. The US and China have reached a tentative agreement on a "phase one" partial trade deal, and the US has suspended tariffs that were due to come into effect on October 15.