Computing the Investor Sentiment Index for Nigeria: Methodology and Applications

Main Article Content

Olusegun J. Ajibola
Olabisi T. Oni
Oladapo G. Awolaja

Abstract

This study computed an Investor Sentiment Index (ISI) for the Nigerian stock market using the Hamilton Filter Decomposition method. The objective is to estimate an Index that reflect Nigerian investor sentiment over the period from January 15, 2009, to November 21, 2024. The Hamilton Filter allows for the separation of long-term trends from short-term cyclical fluctuations, which are then normalized using the min-max approach to create a sentiment index that spans from 0 to 1. The findings from the computed index suggest that investor sentiment generally follows the market’s movements, exhibiting greater volatility during periods of crises, such as the 2008-2011 Global Financial Crisis and the 2020-2021 COVID-19 pandemic. Additionally, sentiment reacts swiftly to news and market changes, making it a leading indicator of market trends, though it does not always align perfectly with the underlying stock index. This research highlights the significant role of investor sentiment in driving market volatility and offers insights into the psychological factors influencing stock prices.

Article Details

How to Cite
Ajibola, O. J. ., Oni, O. T., & Awolaja, O. G. . (2025). Computing the Investor Sentiment Index for Nigeria: Methodology and Applications . African Economic and Management Review, 5(1), 1–9. https://doi.org/10.53790/aemr.v5i1.86
Section
Articles

References

Baker, M., & Wurgler, J. (2006). Investor sentiment and the cross-section of stock returns. Journal of Finance, 61(4), 1645–1680. https://doi.org/10.1111/j.1540-6261.2006.00885.x

Bonaparte, Y. (2025). A flexible framework to extract investors' distraction. Available at SSRN 5079473.

Bouri, E., Gabauer, D., & Gupta, R. (2021). Investor sentiment, stock market performance and the role of economic uncertainty: Evidence from the US. International Review of Financial Analysis, 74, 101634. https://doi.org/10.1016/j.irfa.2020.101634

Cuzzi, D., & Issler, J. V. Oil price predictability and risk premia based on market fundamentals.

Engelberg, J., & Parsons, C. A. (2011). The influence of weather on financial markets: The effect of temperature on the stock market. Journal of Economic Behavior & Organization, 70(1-2), 32–49. https://doi.org/10.1016/j.jebo.2008.06.003

Fama, E. F. (1970). Efficient capital markets: A review of theory and empirical work. Journal of Finance, 25(2), 383–417. https://doi.org/10.1111/j.1540-6261.1970.tb00518.x

Franke, R., Kukacka, J., & Sacht, S. (2024). Is the Hamilton regression filter really superior to Hodrick-Prescott detrending? Extended version. Macroeconomic Dynamics. Extended Version (June 30, 2023). https://doi.org/10.1017/S1365100519000702

Hamilton, J. D. (1989). A new approach to the economic analysis of nonstationary time series and the business cycle. Econometrica, 57(2), 357–384. https://doi.org/10.2307/1912559

Islam, A. (2024). Decomposition of consumer sentiment and the effects of its cyclical component. Available at SSRN 5043483.

Joseph, T., Awolaja, O., & Ajibola, O. (2024). Measuring Sub-Saharan Africa Economic Resilience to External Shocks: The role of Adaptive Policy Space. Applied Journal of Economics, Management and Social Sciences, 5(1), 1–28. https://doi.org/10.53790/ajmss.v5i1.91

Kahneman, D., & Tversky, A. (1979). Prospect theory: An analysis of decision under risk. Econometrica, 47(2), 263–291. https://doi.org/10.2307/1914185

Kim, C.-J., & Nelson, C. R. (1999). Has the business cycle changed and why? In Handbook of Macroeconomics (Vol. 1, pp. 1101–1144). Elsevier. https://doi.org/10.1016/S1574-0048(99)10039-2

Kumar, A., & Lee, C. M. (2006). Retail investor sentiment and market anomalies. Journal of Financial Markets, 9(1), 1–34. https://doi.org/10.1016/j.finmar.2005.03.001

Lee, C. M., Shleifer, A., & Thaler, R. H. (2002). Investor sentiment and the closed-end fund puzzle. Journal of Finance, 57(5), 2077–2091. https://doi.org/10.1111/1540-6261.00498

Musa, D., Awolaja, O., Jerry, K., Okedina, I., Uduakobong, E. E., & Olayinka, I. (2022). Is the influence of oil price changes on oil and gas stock prices in Nigeria symmetric or asymmetric? Cogent Economics & Finance, 10(1), 2154311. https://doi.org/10.1080/23322039.2022.2154311

Shiller, R. J. (2000). Irrational exuberance. Princeton University Press.

Siemers, L. H. (2024). On the Hamilton-HP filter controversy: Evidence from German business cycles (No. 21-2024). MAGKS Joint Discussion Paper Series in Economics.

Tetlock, P. C. (2007). Giving content to investor sentiment: The role of media in the stock market. Journal of Finance, 62(3), 1139–1168. https://doi.org/10.1111/j.1540-6261.2007.01232.x

Vatsa, P., Basnet, H. C., Mixon Jr, F. G., & Upadhyaya, K. P. (2024). Stock markets cycles and macroeconomic dynamics. International Advances in Economic Research, 30(3), 255-278.

Whaley, R. E. (2000). Derivatives on market volatility and the VIX index. Journal of Derivatives, 7(4), 6–23. https://doi.org/10.3905/jod.2000.319351

Yahya, F., & Lee, C. C. (2023). Disentangling the asymmetric effect of financialization on the green output gap. Energy Economics, 125, 106899. https://doi.org/10.1016/j.eneco.2023.106899