Why is Pfizer falling/rising?

As of 19-Sep, Pfizer Ltd. is experiencing a decline in its stock price, currently at 5,110.05, reflecting a decrease of 63.25 points or 1.22%. The stock has underperformed its sector by 1.49% today and has been on a downward trend for the last two days, accumulating a total loss of 1.76% during this period. Over the past week, the stock has dropped by 2.50%, and its performance over the last month shows a significant decline of 9.98%. Despite having a high dividend yield of 3.19% and strong management efficiency indicated by a return on equity of 18.22%, the stock's recent performance is hindered by falling investor participation, with delivery volume decreasing by 44.21% compared to the five-day average.
In the broader market context, Pfizer's recent performance contrasts sharply with the Sensex, which has gained 0.88% over the past week. While the stock has shown a positive return of 24.28% over the last three years, it has underperformed in the short term, with a year-to-date decline of 2.74% compared to the Sensex's increase of 5.74%. This underperformance, coupled with a lack of significant trading activity and a lower position relative to shorter-term moving averages, suggests that investor sentiment may be cautious, contributing to the stock's current decline.