It might turn out to be a grand year. The newly enacted tax cuts should stoke financial markets and lift the economy in 2018. Job growth is strong, and wages are finally ticking up. It helps that most parts of the global economy are improving in sync, reinforcing the worldwide upswing.

But history has definitively demonstrated the danger of complacency, and investors seem too sanguine. There may be no flashing alerts right now, but there are plenty of currents that could form into a storm with little notice. Here are 7 things that could go wrong in 2018:

1. A Trumplosion. Will President Trump be intact at the White House a year from now? Maybe he will be, with competent leaders such as Chief of Staff John Kelly and Defense Secretary Jim Mattis continuing to manage his more disruptive impulses. Yet Trump is a kind of perpetual-chaos machine who routinely tests his own staying power. His new war with former campaign manager Steve Bannon could split Trump’s alt-right base, at the same time special prosecutor Robert Mueller may be zeroing in on Trump’s inner circle, and perhaps Trump himself. None of this means the House of Representatives, controlled by Republicans, would necessarily vote to impeach Trump. But Trump could be far more embattled in 2018 than he was in 2017, and no president is impervious to political pressure.

If Trump were to leave office for some reason, that wouldn’t necessarily be terrible for markets. Vice President Mike Pence, in line to replace Trump if necessary, might be even friendlier toward businesses and markets than Trump is. The worst-case scenario for investors might be a scandal-plagued year in which Trump fights corruption charges, loses allies and burrows into a political bunker, a la President Nixon in pre-resignation 1974—but doesn’t leave. For Trump critics wondering if Trump could become even more controversial and divisive—yes, he could.

2. An outburst of protectionism. Trump is still working to revamp the North American Free Trade Agreement, and he is beginning to revive promises (or threats, if you prefer) of slapping trade sanctions on China. Economists have always worried most about Trump’s trade agenda, since the Cold War-era protectionism he favors involves tariffs and other measures that would raise prices and reduce efficiency, and probably harm growth. Trump might impose nominal trade protections on China and Mexico, while declaring victory, moving on and not changing much in reality. Markets would be fine with that. But if Trump followed through on his pledges to disband NAFTA and slap imports on Chinese tariffs, markets would shudder; they’re not used to bad news.