Investors may not have noticed Boston coronavirus data that goes against the prevailing wisdom. In Boston’s Pine Street Inn, a homeless shelter, 397 people were tested for coronavirus and 146 tested positive but showed no symptoms. The Centers for Disease Control is reviewing the data. There are positive and negative implications for stock market investors — I will discuss those later in this column. The takeaway for investors is that a lot is still unknown about the coronavirus. Until more is known, investors may consider following a simple principle: Neither be a bull nor a bear. Also, remember to do scenario analysis

The rally in the U.S. stock market, which in large part had been due to a short-squeeze, recently exhausted itself. Without positive news, the stock market would have sunk. But stock market bears ran out of luck when a report surfaced Thursday after the close of trading that an antiviral drug, Gilead’s remdesivir, showed promise in treating coronavirus patients. That’s why investors may consider following the simple principle that I have learned in my over 30 years in the markets: Neither be a bull nor a bear. Over time, the practical way to use this principle has become encapsulated in