If you must limit yourself to only two macro risks worthy of flaring up your insomnia they are these:
1.) Trade war contagion – Globalization and open borders are going out of style in mainstream developed market politics. Fast. In theory, trade reform can be targeted to narrow trade deficits, increase wages for the middle class, and make every developed country great again. In reality, there are tremendous risks of unintended consequences shaking the foundation of modern global economies. Modern economies function with tightly intertwined international supply chains. What would happen if every US import from Mexico, China, or even Germany rose in price by 15-20% at the stroke of a legislative pen? Would it really stop there? Would it not spark a wave of race-to-the-bottom retaliations, currency devaluations, and nasty inflation eroding real incomes across the board? This is the top known economic and market risk as 2017 swings into gear. Pay attention to statements of pre-retaliation by public officials in trade-dominated economies.
2.) China’s currency reserves burn rate – China is burning through reserves at an alarming rate to prop up the yuan rather than suppressing it for competitive purposes as commonly alluded to by US President Trump. It has depleted more than 25% of its currency reserves in the past 1 1/2 years. It may only have another 6-18 months left before it is forced into a massive yuan devaluation of at least 15% to stop the bleeding. This would increase pressure on other Asian economies to also devalue their currencies, inflict trauma on US exporters and multinationals, compound default risk for dollar-denominated debtors, and destabilize financial markets. Imagine the turbulence seen in August of 2015 multiplied by at least 10; then tack on second-round effect multipliers. It is certainly worthy of being on the top macro risk short list.
Honorable mention goes to political election risk in the Eurozone this year. This will be a topic covered in more detail on this site in the future.