Here's how the stock market declined in 2018 from the peak in January and the peak in October as compared to the current peak.
I also have graphed the levels of support from previous panic selloffs as represented by the pink triangles and lines. Usually those are reference levels for support for the market.
Notice what happened back in late 2018 when the previous support levels were tested in October 2018 and November 2018, then broke and washed out the market into year-end 2018.
CoronaVirus is a powerful force here that is dynamically impacted the market on a moment-to-moment basis. Anything can happen.