Summary:
BSE's inclusion in the Nifty 50 triggered heavy portfolio rebalancing on September 29, 2026. NSE's closing auction turnover reached ₹24,504 crore, with BSE shares accounting for ₹6,247 crore as passive funds and investors adjusted holdings following the index reshuffle.
The inclusion of Bombay Stock Exchange (BSE) in the Nifty 50 index created an unusual surge in market activity as investors and passive funds adjusted their portfolios ahead of the benchmark index reshuffle. The closing auction session (CAS) on September 29 witnessed turnover of ₹24,504 crore, making it the second-highest single-session turnover recorded by the exchange.
BSE became the centre of attraction as index funds, exchange-traded funds (ETFs) and other investors tracking the Nifty 50 rushed to align their holdings with the new index composition. Around 19.52 million BSE shares worth ₹6,247 crore changed hands during the closing auction, accounting for more than one-fourth of the total CAS turnover.
The move came after BSE replaced Wipro in the Nifty 50 index as part of the semi-annual index rebalancing exercise. The inclusion increased demand for BSE shares from passive investment products that replicate benchmark indices.
BSE share price gains as passive inflows boost sentiment
BSE shares ended the session 3.31% higher compared with the previous close, with a significant portion of the day’s gains coming during the closing auction. The stock was trading around ₹3,200 levels and remained more than 27% below its 52-week high of ₹4,403 touched on May 26, 2026.
The market reaction reflected expectations that Nifty 50 inclusion could bring additional institutional participation and improve visibility among global and domestic investors. However, the longer-term movement of the stock will depend on broader business factors, including competition dynamics, market share trends and regulatory developments.
Why trading volumes surged across the market
The sharp rise in volumes was not limited to BSE alone. Wipro, which moved from the Nifty 50 to the Nifty Next 50 index, also witnessed heavy activity as investors adjusted their portfolios. Around 130.17 million Wipro shares worth ₹2,041 crore changed hands during the closing auction.
The unusual volatility was driven by the combination of multiple events occurring on the same day — the Nifty index reshuffle, monthly derivatives expiry and portfolio rebalancing activity. During the closing auction, the Nifty’s indicative closing level briefly fell 431 points within nearly two and a half minutes before recovering the entire decline by the end of the session.
Market impact: Nifty sees volatile expiry session
The broader market remained under pressure despite the heavy trading activity. The Nifty 50 closed at 22,716.20, down 0.28%, while the Sensex declined 0.33% to 72,529.07 on September 29.
The sharp swings were largely attributed to derivatives-related activity, including rollover positions and expiry-day adjustments. Market participants had anticipated higher volatility because index rebalancing and monthly expiry coincided in the same session.
What does Nifty 50 inclusion mean for BSE?
Entry into the Nifty 50 provides BSE with greater representation among institutional investors and index-linked products. The inclusion may increase passive fund ownership because funds tracking the benchmark index need to hold constituent stocks.
However, index inclusion alone does not determine the company’s long-term performance. Factors such as exchange volumes, derivatives market share, regulatory framework and competitive positioning will continue to influence BSE’s future trajectory.
The September 29 session highlighted how index changes can create large short-term movements in stocks and trading volumes, especially when combined with derivatives expiry and institutional portfolio adjustments.
