Keep Your Head During These Wild Markets: Northern Trust

"Through March 17, it has been painful," Browne agreed, but he highlighted that in a bear market the average drop was 33% with an average recuperation time of 254 days. However, bull markets last three times longer than a bear market on average, with a 96% average gain.

Although the stock market gets most coverage, Browne saw some key areas to watch:

• Oil markets: With crude oil dropping 30% from its previous close on March 9 (and falling $45 since Jan. 8 through March 17), Northern Trust looked back to see this kind of oil drop's effect on various financial indexes. They found that the best index performance after an oil price drop was the U.S. Aggregate Bond index, followed by the Global Aggregate Bond Index. Six month after a major drop, the U.S. AB was up 5%, up 10% after 12 months and up 20% after 24 months. Similarly, the index was up 2% after six months, 6% after 12 months and 16% after 24 months. In comparison, the MSCI ACWI ex. U.S. was down 9% after six months, down 12% after 12 months and down 10% after 24 months.

On Wednesday, oil dropped 24% to an 18-year low.

"Oil prices do have an impact on the bond market for 12-24 months. Bond yields remain low for an uncertain length of time, and international equities take longer to rebound," Browne said.

• Central banks: The Federal Reserve and its global counterparts have been aggressive in easing during this crisis, especially with the Fed's emergency slashing of interest rates to 0.25%. EU rates are already at 0%, while Japan is at negative rates. Browne says they don't see the Fed reversing this decision anytime soon. "We are in a low rate and accommodative policy for an extended period of time, which has implications for long-term cash flows."

Historically, though, when the Fed eases, the best performers again are U.S. and Global Aggregate Bond indexes, he said.

Two key risks to keep an eye on, Browne said, are failed governmental efforts to contain the virus and geopolitical skirmishes, such as Russia 's oil price war, that may offset some "virus-driven policy efforts."

Northern Trust has adjusted its portfolio to be overweight high-yield bonds, U.S. equities (income oriented) and global listed infrastructure and real estate.

Browne says the firm sees the coronavirus being "front and center for a period of time. Cases peaked out [in China] at four to six weeks, but it remains to be seen [what happens in the United States]. It depends on how people respond," he said. "A re-emergence of the virus in China and India is possible."

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