Why is Glaxosmi. Pharma falling/rising?

As of 05-Sep, Glaxosmithkline Pharmaceuticals Ltd is experiencing a decline in its stock price, currently at Rs 2,776.90, reflecting a decrease of Rs 58.5 or 2.06%. The stock has underperformed its sector by 1.99% today and has seen a trend reversal after two consecutive days of gains. It touched an intraday low of Rs 2,764, indicating a drop of 2.52%. Over the past week, the stock has decreased by 0.24%, and over the past month, it has fallen by 2.23%. Despite a strong year-to-date performance of 23.60%, the stock's one-year return is down by 1.42%. The company maintains a high management efficiency with a return on equity of 42.32% and a low debt-to-equity ratio, which are positive factors, but these have not been sufficient to counteract the recent price decline.
In the broader market context, the Sensex has increased by 1.13% over the past week, contrasting with Glaxosmithkline's negative return during the same period. This underperformance against the benchmark may indicate a lack of investor confidence or sector-specific challenges affecting the stock. The rising investor participation, with a delivery volume increase of 17.25% against the five-day average, suggests some interest in the stock, but it has not translated into price stability. Overall, while the stock has shown strong performance over the long term, recent movements indicate a struggle to maintain momentum in the face of broader market gains.