Author: Dhwani Gupta
Introduction:
Dr. Reddy’s Laboratories is a leading Indian multinational pharmaceutical company. In finance, evaluating a stock’s performance relative to a market benchmark (like the NIFTY 50) is essential for understanding its risk-return profile. This analysis uses the Capital Asset Pricing Model (CAPM) framework to determine the stock’s systematic risk, commonly known as Beta.
Objective:
The primary objectives of this analysis are:
- To calculate the Beta of Dr. Reddy’s Laboratories to assess its sensitivity to market movements.
- To evaluate the statistical significance of the relationship between the stock and the index.
- To analyze the volatility and return characteristics of the stock compared to the benchmark.
Literature Review:
In financial theory, the Capital Asset Pricing Model (CAPM) posits that the expected return of an asset is a function of the risk-free rate and a risk premium based on the asset’s Beta.
- Beta: Measures the systematic risk. A beta > 1 implies the stock is more volatile than the market (aggressive), while a beta < 1 implies it is less volatile (defensive).
- R-Squared (R^2): Represents the proportion of the variance for a dependent variable that’s explained by an independent variable in a regression model.
- Alpha: Represents the excess return of an investment relative to the return of a benchmark index.
· Regression Equation: The relationship is modeled as:
 |
Ri = Alpha + Beta (Rm) + Epsilon
Where Ri is the stock return, Rm is the market return, alpha is the intercept (excess return), and epsilon is the error term.
Data Collection:
The data consists of weekly closing prices and returns for:
- Dependent Variable (Y): Dr. Reddy’s Laboratories (Stock).
- Independent Variable (X): NIFTY 50 (Market Index).
- Timeframe: December 1, 2024, to November 30, 2025 (48 weekly observations).
- Source: National Stock Exchange (NSE) via the provided CSV dataset.
Data Analysis:
The analysis was performed using linear regression on the weekly returns of the stock and the index.
Descriptive Statistics
|
Metric |
Dr. Reddy’s (Stock) |
NIFTY 50 (Index) |
|
Mean Weekly Return |
0.049% |
-0.108% |
|
Standard Deviation (Volatility) |
3.43% |
1.88% |
|
Minimum Weekly Return |
-7.24% |
-5.04% |
|
Maximum Weekly Return |
7.18% |
5.01% |
Regression Results
Based on the regression analysis:
- Beta: 0.7307
- Interpretation: Dr. Reddy’s is a defensive stock. For every 1% move in the NIFTY 50, the stock is expected to move by 0.73%.
- R-Squared (R^2): 0.1606
- Interpretation: Only about 16 of the stock’s price movement is explained by the market. The remaining 84% is due to idiosyncratic risk (company-specific factors like drug approvals, R&D results, or earnings).
- P-Value: 0.0048
- Interpretation: Since the p-value is less than 0.05, the relationship between the stock and the index is statistically significant at a 95% confidence level.
- Alpha: 0.1277
- Interpretation: The stock provided a small positive average excess return over the market during this period, independent of market movements.
-
Regression Equation:
Dr. Reddy (Y) = 0.1277 + 0.7307 (Nifty 50 X)
Conclusion:
The analysis reveals that Dr. Reddy’s Laboratories acts as a defensive investment with a Beta of 0.73. While the stock itself is more volatile (Standard Deviation of 3.43%) than the index (1.88%), its sensitivity to broad market swings is lower.
The low R-squared suggests that an investor in Dr. Reddy’s is primarily exposed to pharmaceutical industry-specific risks rather than general market trends. This makes it a good candidate for portfolio diversification, as it does not move perfectly in sync with the NIFTY 50.
References:
- Sharpe, W. F. (1964). Capital Asset Prices: A Theory of Market Equilibrium under Conditions of Risk. Journal of Finance.
- Bodie, Z., Kane, A., & Marcus, A. J. (2021). Investments. McGraw-Hill Education.
- Damodaran, A. (2012). Investment Valuation: Tools and Techniques for Determining the Value of Any Asset. Wiley.