Fear of the unknown, as the coronavirus continues to spread, is what economic advisor Hugh Johnson says is driving most of the ongoing panic on Wall Street.

“If there is one word that really summarizes the whole problem, it is the word ‘uncertainty,’ ” Johnson said Monday morning. “Investors are saying really clearly this could develop into something very serious; in other words, an economic recession.”

Shortly after the markets opened Monday, stock prices plummeted. By the end of the day, the Dow Jones had dropped by 7.8 percent.

In order to slow the bleeding early in trading, the extremely rare decision was made to pause trading for 15 minutes.

"[You] get everybody to sober up and say 'let’s take a more sensible assessment of the level of prices and make sensible decisions,' ” Johnson said.

Johnson says much of the concern comes from American companies not being able to get products from manufacturers in Asia, where coronavirus' impact has been more severe.

"It’s going to show up in their revenues and their earnings,” Johnson said.

Johnson says a steep decline in oil prices is making matters even worse for American energy companies. The world's two largest producers, Russia and Saudi Arabia, are involved in an ongoing dispute, and both are threatening to ramp up production; throwing the global supply out of whack.

“You're going to have a lot of companies that are going to shut down their production facilities and that’s going to be bad news globally,” he said.

With the markets on such unstable footing, Johnson says it can be hard for investors to determine their next steps.

"When you see this going on, it scares the heck out of them, it does, and it scares me too,” Johnson said.

While he expects prices to drop further, Johnson says look for the silver lining: Many stocks are now available for a discount.

“If you are a small investor, you might use this as an opportunity to buy, but do not use up all of your ammunition at once," Johnson said.

Most importantly, Johnson says don't do anything rash, especially when it comes to retirement accounts.

“The one piece of advice I would give everybody is try not to get caught up in it emotionally, and recognize over long periods of time, you are going to be just fine,” Johnson said.