Sensex, Rupee and FII Flows Move Together: What Bank of Baroda's New Study Reveals

India's benchmark equity index, the Sensex, has become increasingly intertwined with foreign investor activity and the strength of the Indian Rupee, according to a new study by Bank of Baroda.

The report suggests that stock market performance, foreign capital inflows and currency movements are not operating independently. Instead, they are influencing one another in ways that have become even more pronounced in the post-pandemic period.

What Did the Study Find?

The Bank of Baroda study found a strong positive relationship between the Sensex and Foreign Institutional Investor (FII) flows, indicating that foreign investment tends to rise when the stock market strengthens and decline when it weakens.

The report also found a similar positive relationship between the Sensex and the Rupee, suggesting that a stronger stock market is often associated with a stronger domestic currency.

According to the study, these relationships strengthened significantly between April 2022 and March 2026. During this period, the correlation coefficient between the Sensex and the Rupee reached 0.6, while the correlation between the Sensex and FII flows stood at 0.7.

Understanding Positive Correlation

The report explained that a positive correlation means two variables move in the same direction.

The study noted that a positive correlation indicates a mirror relationship where a change in one variable, whether an increase or a decrease, moves the other variable in the exact same direction. Conversely, a negative correlation means the variables move in opposite directions.

In practical terms, this means that rising stock markets have often coincided with stronger foreign investment inflows and a firmer Rupee, while declines in one have generally been accompanied by weakness in the others.

Why Has the Relationship Become Stronger?

The study analysed macroeconomic indicators from fiscal year 2000 through fiscal year 2026 and found that the links among the Sensex, the Rupee and FII flows have become more pronounced in the years following the Covid-19 pandemic.

"Additionally, INR and FII flows also reflect a positive correlation. Notably, a higher level of positive correlation has been noted in the post covid series between each of the variables," the report said.

This suggests that financial markets, foreign capital and currency movements are now reacting more closely to the same economic and global factors than they did in earlier periods.

What Is the Spillover Effect?

One of the key findings of the study is the existence of a spillover effect within Indian financial markets.

The report found that past movements in the Sensex can influence future market behaviour, a phenomenon often associated with volatility clustering.

The report mentioned, "given the presence of volatility clustering, it has been observed that there is a spillover effect between the changes in the past Sensex returns to their future outcome."

In simple terms, periods of strong gains or losses in the stock market can continue to influence investor behaviour and market volatility in subsequent periods.

How Do FIIs and the Rupee Fit Into This?

The study found evidence that stock market movements can affect foreign investor activity as well.

"The same can also be said for FIIs, but might not be true for INR as one of the coefficients in the mean equation for INR was not significant," the report added.

This means that while foreign investment patterns appear to be influenced by earlier market movements, the relationship with the Rupee may be more complex and not always statistically consistent.

Can the Sensex Influence the Exchange Rate?

According to the report, market performance may even have an impact on currency movements under certain conditions.

"Furthermore, the spillover effect has been noted with changes in Sensex return, which can sometimes lead to changes in exchange rate, since one model validates this result," the study report added.

The findings suggest that strong equity market performance can help shape investor sentiment, capital flows and, in turn, currency dynamics.

Impact on Foreign Investors

The report also highlighted that changes in the Sensex can influence the volatility of foreign investment flows.

"Change in Sensex return also has a volatility spillover effect on FIIs. Therefore, changes in the Sensex returns do actually influence the volatility of FIIs."

This underscores the growing interconnectedness of India's financial ecosystem, where equity markets, foreign capital and currency movements increasingly respond to one another.

The Bottom Line

The Bank of Baroda study paints a picture of a closely linked financial environment in which the Sensex, FII flows and the Rupee move together more strongly than in the past. The findings indicate that stock market performance not only reflects investor confidence but may also influence foreign capital behaviour and, to some extent, currency movements, reinforcing the deep connections across India's financial markets.

(With inputs from ANI)