Despite some tumultuous twists and turns, the U.S. stock market made big gains in 2014. But the new year has got off to a rough start with a market-wide sell-off.

In 2014, the Dow Jones Industrial Average gained 7.5% as it crossed both the 17,000-point and 18,000-point marks for the first time ever. The S&P 500 posted 53 record highs as it rose 12% on the year while the tech-heavy Nasdaq composite jumped more than 13% to its highest levels since the dot-com bubble burst in 2000.

But this year, the Dow has already lost more than 2.5%, and it is more than 700 points behind its record levels of just weeks ago. Both the S&P 500 and the Nasdaq have also dropped by roughly 3% during that time because of concerns about the European economy and falling oil prices.

Despite 2014’s record levels, this year’s slow start has some market analysts declaring an end to the bull market and predicting that Wall Street’s bear is emerging from hibernation. Here are some reasons why 2015 might be a disappointing year for the stock market: