One of my friends got this question during an interview. He asked about my opinion. Honestly I dont have any clue. The question is as follows:
Assume we fit a machine learning model to predict the stock prices of the stock XXX. The model was trained and evaluated before COVID. It was then used to predict the future prices(Before COVID). The data during COVID is pretty much new to this model. (The model hasn't seen that type of incident before). What should we do to get the accurate predictions during the COVID?