Evolving Weak Form Market Efficiency in BRICS+ Markets
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Rifka Indi*
Danes Quirira Octavio
Adhi Widyakto
The Efficient Market Hypothesis (EMH), particularly in its weak form, remains a subject of debate, especially in emerging and developing markets where structural, institutional, and behavioral factors may hinder informational efficiency. The recent enlargement of the BRICS group to BRICS+ now includes a wider range of diverse economies. Therefore, a thorough reexamination of weak‑form market efficiency across these markets is required. This study explores weak‑form efficiency in BRICS+ stock markets and determines if stock returns follow a random walk or display predictable trends over time. This study analyzes daily returns of nine stock indexes including Brazilian, Russian, Indian, Chinese, South African, Saudi Arabia, Egyptian, and United Arab Emirates, and Indonesian between January 2006 and December 2024. We employed run tests, unit root tests (Augmented Dickey-Fuller and Phillips-Perron), and variance ratio tests to determine the randomness and predictability of returns. Conflicting evidence emerges from the empirical analysis of weak‑form efficiency. On one hand, randomness is supported by both run tests and unit root tests for every BRICS+ index. On the other hand, variance ratio tests produce significant results that contradict the random walk hypothesis. Such opposing findings indicate that BRICS+ stock markets are not consistently weak‑form efficient. They instead confirm the Adaptive Market Hypothesis, a framework that is only partially applicable and varies with context. This hypothesis is influenced by evolving economic circumstances, the maturity of institutions, and the actions of investors. It highlights the need to adopt adaptive investment strategy and flexible regulation strategies in dynamic market environments.
Abrosimova, N., Dissanaike, G., & Linowski, D. (2002). Testing Weak-Form Efficiency of the Russian Stock Market. SSRN Electronic Journal. https://doi.org/10.2139/ssrn.302287
Arltova, A. J. (2000). Variance ratios, socio-economical applications of statistical methods. In Wroclaw University of Economics Publishing House. Wroclaw University of Economics Publishing House.
Barberis, N., Shleifer, A., & Vishny, R. (1998). A model of investor sentiment. Journal of Financial Economics, 49(3), 307-343. https://doi.org/10.1016/S0304-405X(98)00027-0
Ben Salem, S., & El Aoun, O. (2025). Banking index volatility and spillover effects in G7 and BRICS economies: a quantile connectedness approach. Studies in Economics and Finance, 42(4), 836-864. https://doi.org/10.1108/SEF-01-2025-0046
Bertone, S., Paeglis, I., & Ravi, R. (2015). Has the market become more efficient? Journal of Banking & Finance, 54, 72-86. https://doi.org/10.1016/j.jbankfin.2014.12.019
Bocher, R. (2022). The Intersubjective Markets Hypothesis. Journal of Interdisciplinary Economics, 34(1), 35-50. https://doi.org/10.1177/02601079211032109
Bondt, W. F. M. De, & Thaler, R. (1985). Does the Stock Market Overreact? The Journal of Finance, 40(3), 793. https://doi.org/10.2307/2327804
Borges, M. R. (2010). Efficient market hypothesis in European stock markets. The European Journal of Finance, 16(7), 711-726. https://doi.org/10.1080/1351847X.2010.495477
Busse, J. A., Goyal, A., & Wahal, S. (2010). Performance and Persistence in Institutional Investment Management. The Journal of Finance, 65(2), 765-790. https://doi.org/10.1111/j.1540-6261.2009.01550.x
Campbell, J. Y., Lo, A. W., MacKinlay, A. C., & Whitelaw, R. F. (1998). The Econometrics of Financial Markets. Macroeconomic Dynamics, 2(4), 559-562. https://doi.org/10.1017/S1365100598009092
Carhart, M. M. (1997). On Persistence in Mutual Fund Performance. The Journal of Finance, 52(1), 57-82. https://doi.org/10.1111/j.1540-6261.1997.tb03808.x
Chen, C.-P., & Metghalchi, M. (2012). Weak-Form Market Efficiency: Evidence from the Brazilian Stock Market. International Journal of Economics and Finance, 4(7). https://doi.org/10.5539/ijef.v4n7p22
Chong, T. T.-L., Cheng, S. H.-S., & Wong, E. N.-Y. (2010). A Comparison of Stock Market Efficiency of the BRIC Countries. Technology and Investment, 1(4), 235-238. https://doi.org/10.4236/ti.2010.14029
Chow, K. V., & Denning, K. C. (1993). A simple multiple variance ratio test. Journal of Econometrics, 58(3), 385-401. https://doi.org/10.1016/0304-4076(93)90051-6
Cortés Rufé, M., & Martí Pidelaserra, J. (2024). Mapping financial connections: Market integration in emerging economies through graph theory. Risks, 12(10), 154. https://doi.org/10.3390/risks12100154
Ekananda, M. (2016). Analisis Ekonometrika Time Series (2nd ed.). Mitra Wacana Media.
Fama, E. F. (1970). Efficient capital markets: A review of theory and empirical work. The Journal of Finance, 25(2), 383-417. https://doi.org/10.2307/2325486
Fama, E. F., & French, K. R. (2010). Luck versus Skill in the Cross‐Section of Mutual Fund Returns. The Journal of Finance, 65(5), 1915-1947. https://doi.org/10.1111/j.1540-6261.2010.01598.x
Fifield, S. G. M., & Jetty, J. (2008). Further evidence on the efficiency of the Chinese stock markets: A note. Research in International Business and Finance, 22(3), 351-361. https://doi.org/10.1016/j.ribaf.2008.02.002
Fusthane, O., & Kapingura. (2017). Weak Form Market Efficiency of the Johannesburg Stock Exchange: Pre, During and Post the 2008 Global Financial Crisis. Journal of Economics and Behavioral Studies, 9(5(J)), 29-42. https://doi.org/10.22610/jebs.v9i5(J).1907
Gujarati, D. N. (2010). Dasar-dasar Ekonometrika (5th ed.). Salemba Empat.
Gupta, R., & Yang, J. (2011). Testing weak form efficiency in the indian capital market. International Research Journal of Finance and Economics, 75, 108-119.
Hadhri, S., & Ftiti, Z. (2017). Stock return predictability in emerging markets: Does the choice of predictors and models matter across countries? Research in International Business and Finance, 42, 39-60. https://doi.org/10.1016/j.ribaf.2017.04.057
Hiremath, G. S., & Kumari, J. (2014). Stock returns predictability and the adaptive market hypothesis in emerging markets: evidence from India. SpringerPlus, 3(1). https://doi.org/10.1186/2193-1801-3-428
Kahneman, D., & Tversky, A. (2013). Prospect theory: An analysis of decision under risk. In Handbook of the fundamentals of financial decision making: Part I (pp. 99-127). World Scientific.
Kheradyar, S., Ibrahim, I., & Nor, F. M. (2011). Stock Return Predictability with Financial Ratios. International Journal of Trade, Economics and Finance, 391-396. https://doi.org/10.7763/IJTEF.2011.V2.137
Kim, Y. (2025). Efficient Market Testing of the Thai Stock Market During the COVID-19 Recession. Global Business Finance Review, 30(1), 1-12. https://doi.org/10.17549/gbfr.2025.30.1.1
Kleinheyer, M., & Mayer, T. (2020). Discovering Markets. Quarterly Journal of Austrian Economics, 23(1), 3-32. https://doi.org/10.35297/qjae.010050
Kulikova, M. V., Taylor, D. R., & Kulikov, G. Y. (2024). Evolving efficiency of the BRICS markets. Economic Systems, 48(1), 101166. https://doi.org/10.1016/j.ecosys.2023.101166
Lettau, M., & Van Nieuwerburgh, S. (2008). Reconciling the Return Predictability Evidence. Review of Financial Studies, 21(4), 1607-1652. https://doi.org/10.1093/rfs/hhm074
Lim, K.-P., Habibullah, M. S., & Hinich, M. J. (2009). The Weak-form Efficiency of Chinese Stock Markets. Journal of Emerging Market Finance, 8(2), 133-163. https://doi.org/10.1177/097265270900800203
Liu, T. (2011). Market Efficiency in China Stock Market and Hong Kong Stock Market. International Research Journal of Finance and Economics, 128-137.
Lo, A. W. (2004). The Adaptive Markets Hypothesis. The Journal of Portfolio Management, 30(5), 15-29. https://doi.org/10.3905/jpm.2004.442611
Lo, A. W., & MacKinlay, A. C. (1988). Stock Market Prices Do Not Follow Random Walks: Evidence from a Simple Specification Test. Review of Financial Studies, 1(1), 41-66. https://doi.org/10.1093/rfs/1.1.41
Lock, D. B. (2007). The Taiwan stock market does follow a random walk. Economics Bulletin, 7(3), 1-8.
Malafeyev, O., Awasthi, A., S.Kambekar, K., & Kupinskaya, A. (2019). Random Walks and Market Efficiency in Chinese and Indian Equity Markets. Statistics, Optimization & Information Computing, 7(1), 1-25. https://doi.org/10.19139/soic.v7i1.499
Mandaci, P. E., Taskin, F. D., & Ergun, Z. C. (2019). Adaptive Market Hypothesis. International Journal of Economics & Business Administration (IJEBA), 7(4), 84-101. https://doi.org/10.35808/ijeba/333
Mangee, N. (2021). How Novelty and Narratives Drive the Stock Market: Black Swans, Animal Spirits and Scapegoats. Cambridge University Press.
McGowan, Jr., C. B. (2011). An Analysis Of The Technical Efficiency Of The Russian Stock Market. International Business & Economics Research Journal (IBER), 10(10), 31. https://doi.org/10.19030/iber.v10i10.5977
McGowan, Jr., C. B., & Ibrihim, I. (2009). An Analysis of The Day-Of-The-Week Effect In The Russian Stock Market. International Business & Economics Research Journal (IBER), 8(9). https://doi.org/10.19030/iber.v8i9.3165
Mobarek, A., & Fiorante, A. (2014). The prospects of BRIC countries: Testing weak-form market efficiency. Research in International Business and Finance, 30, 217-232. https://doi.org/10.1016/j.ribaf.2013.06.004
Mobarek, A., Mollah, A. S., & Bhuyan, R. (2008). Market Efficiency in Emerging Stock Market. Journal of Emerging Market Finance, 7(1), 17-41. https://doi.org/10.1177/097265270700700102
Muller, U. A., Dacorogna, M. M., Dave, R. D., Pictet, O. V., Olsen, R. B., & Ward, J. R. (1995). Fractals and Intrinsic Time: A Challenge to Econometricians. International Conference of the Applied Econometrics Association (AEA).
Nalin, H. T., & Guler, S. (2015). Testing The Random Walk Hypothesis: An Application in the BRIC Countries and Turkey. Romanian Economic Journal.
Nguyen, J., & Parsons, R. (2022). A Study of Market Efficiency in Emerging Markets Using Improved Statistical Techniques. Emerging Markets Finance and Trade, 58(7), 2004-2016. https://doi.org/10.1080/1540496X.2021.1949981
Nyakurukwa, K., & Seetharam, Y. (2023). Alternatives to the efficient market hypothesis: an overview. Journal of Capital Markets Studies, 7(2), 111-124. https://doi.org/10.1108/JCMS-04-2023-0014
Peón, D., Antelo, M., & Calvo, A. (2019). A guide on empirical tests of the EMH. Review of Accounting and Finance, 18(2), 268-295. https://doi.org/10.1108/RAF-02-2016-0031
Peters, E. E. (1994). Fractal Market Analysis: Applying Chaos Theory to Investment and Economics (1st ed.). Wiley.
Phillips, P. C. B., & Perron, P. (1988). Testing for a unit root in time series regression. Biometrika, 75(2), 335-346. https://doi.org/10.1093/biomet/75.2.335
Poshakwale, S. (1996). Evidence on weak form efficiency and day of the week effect in the Indian stock market. Finance India, 10(3), 605-616.
Sayed, A., & Charteris, A. (2024). Integration among the BRICS stock markets: Filtering out global factors. Investment Analysts Journal, 53(3), 207-230. https://doi.org/Integration among the BRICS stock markets: Filtering out global factors
Shiller, R. J. (1981). Do Stock Prices Move Too Much to be Justified by Subsequent Changes in Dividends? American Economic Review, 71(3), 421-436. https://doi.org/10.3386/w0456
Shleifer, A., & Summers, L. H. (1990). The Noise Trader Approach to Finance. Journal of Economic Perspectives, 4(2), 19-33. https://doi.org/10.1257/jep.4.2.19
Vaga, T. (1990). The Coherent Market Hypothesis. Financial Analysts Journal, 46(6), 36-49. https://doi.org/10.2469/faj.v46.n6.36
Verheyden, T., De Moor, L., & Van den Bossche, F. (2015). Towards a new framework on efficient markets. Research in International Business and Finance, 34, 294-308. https://doi.org/10.1016/j.ribaf.2015.02.007
Worthington, A., & Higgs, H. (2006). Weak-Form Market Efficiency in Asian Emerging and Developed Equity Markets: Comparative Tests of Random Walk Behaviour. Accounting Research Journal, 19(1), 54-63.
Xiong, X., Meng, Y., Li, X., & Shen, D. (2019). An empirical analysis of the Adaptive Market Hypothesis with calendar effects:Evidence from China. Finance Research Letters, 31. https://doi.org/10.1016/j.frl.2018.11.020
Yen, G., & Lee, C. (2008). Efficient Market Hypothesis (EMH): Past, Present and Future. Review of Pacific Basin Financial Markets and Policies, 11(02), 305-329. https://doi.org/10.1142/S0219091508001362
