9 Mar 2020 Pfizer (PFE) is one of the biggest pharmaceutical companies in terms of market valuation. Earnings also slipped 13%, deepening from a 3% fall in the third quarter. The RS Line compares a stock's price action with that of the S&P 500. In after-hours trading on the stock market today, Forty Seven stock 21 Sep 2019 26, 2018, social media giant Facebook Inc. (FB) became the largest company to see a one-day decline in its stock price wipe more than $100 Data is currently not available.