Time Series Analysis in Pfizer Stock Prices in the Pre- and Post-COVID-19 Scenarios

Pfizer is a multinational pharmaceutical company that specializes in the research, development, manufacturing, marketing, and sale of pharmaceuticals. When it comes to the pharmaceutical industry, Pfizer is a major player, and it has developed phase-3 study COVID-19 vaccine on November 9, 2020, which provided a positive impact on stock prices and distinguishes Pfizer stock price trends from other companies. This research focus on the Pfizer stock price which comes from Yahoo Finance website to compare difference model performance of Pfizer stock price forecasting and test if the stock market’s trend before and after the COVID-19 outbreak is distinct. The result shows the LSTM had a best performance and in the next year, Pfizer stock price will stay at around 43 after a sharp decrease. And the vaccine has a statistically significant effect on the stock price. This essay provides a forecast regarding the pattern of recovery throughout the period after the COVID-19 pandemic.