By all rights, 2016 should be a good year for the U.S. stock market.
The Federal Reserve's recent rate hike signals confidence in the economy and presidential election years typically reward investors. Most experts are predicting a seventh year for the current bull market, with strategists in a recent poll expecting the Standard & Poor's 500 stock index to end 2016 at about 2,207, roughly 8 percent higher than it is now.
But a lot could go wrong. The same strategists have cataloged a long list of worries - everything from a destabilizing U.S. election to a meltdown far away - that could hit stocks hard.
Here is their laundry list of concerns. For those who'd rather stay optimistic, remember the old chestnut: Wall Street climbs a wall of worry.
Companies Might Stop Earning Profits
Most of the 30 strategists polled by Reuters cited weak earnings as their prominent concern. With S&P earnings growth projected to be flat in 2015, stocks already are pricey. The market is trading at roughly 19.3 times trailing earnings, well above its 15 average. Any stumble in earnings would make stocks even pricier.
Thomson Reuters analysts now expect revenue to grow 3.9 percent in 2016, meaning any increases in costs could keep earnings flat for a second year in a row.
"If labor costs start moving up a bit and interest expense is moving up ... it's going to be hard to keep margins up," said Bob Doll, chief equity strategist at Nuveen Asset Management in Princeton, New Jersey.
Strong Dollar Could Keep Inflicting Pain
The dollar, up 8.4 percent against a basket of currencies in 2015, is expected to see further gains next year as the United States hikes rates while other countries continue easy money policies.