Opportunity To Gain
Don't think that needed much elaboration as crisis regardless of its nature is always short term.  In the process stock prices will be battled down to many consider as cheap bargain and with a long time frame, picking up those cheap bargain especially stocks with good fundamental will more or less warrant a profit in the future.  Another way is the short term gain when taking out short positions during the crisis.

Opportunity To Learn
You can only learn when there is a mistake, wrong decision, bad timing or inappropriate action.  Thus, putting on a rational and logic hat to do a microscopic examination is the only way to dig out all those.  The Covid-19 virus outbreak since catching