5. Why the bull market's days could be numbered

The coronavirus outbreak has sent markets into a tailspin. The outbreak overshadowed an otherwise solid fourth quarter 2019 earnings season, and will further weigh on companies going forward — some including Apple and Microsoft have warned that they might not hit future earnings guidance numbers or have even withdrawn estimates in light of the outbreak. Goldman Sachs now estimates that US companies will post zero earnings growth in 2020 because of coronavirus.

In addition, the US economy is likely to take a hit as the coronavirus disrupts supply chains, keeps workers at home, and potentially hinders consumer confidence. While the Federal Reserve issued an emergency rate cut to spur the US economy, markets haven't reacted positively — stocks have continued to fall while long-term US Treasury bonds rally, showing that traders are still banking on further cuts from the central bank.

If markets continue to fall, it could mark the end of the bull market. It's possible that the market could fall into bear territory — a drop of 20% or more from the recent high — is according to Lori Calvasina, head of US equity strategy at RBC. That could send the US into a recession.