COVID-19 is already having a large impact on global markets and economies. The US Federal Reserve did an emergency out of meeting 0.5% rate cut (only the 8th in over twenty years) and Goldman Sachs are saying that US earnings growth will be minimal in Q1 2020, perhaps even zero.
The issue is that this is a supply side risk rather than just demand side and that makes it much harder to combat and certainly the Fed rate cut will have little impact as witnessed by US markets falling some 2.5% after the cut was announced.
This is going to get worse before it gets better and investors need to be ready for the full implications to their portfolio as well as look at ways of defending their investments.