SEBI Proposal to Eliminate NSE-BSE Price Gaps Could Improve Execution for Retail Investors

The Securities and Exchange Board of India (SEBI) has proposed a mechanism to harmonise price bands across the National Stock Exchange (NSE) and Bombay Stock Exchange (BSE), addressing a long-standing market inefficiency that has particularly affected investors in illiquid stocks.

Under the proposal, when a stock remains untraded on one exchange but trades on the other, the inactive exchange would be required to adopt the active exchange's closing price as the reference price for the next trading session. The move aims to eliminate pricing discrepancies, improve price discovery and ensure fairer execution for retail investors.

Why Do Price Gaps Occur?

India's equity market is unique in that thousands of stocks are listed and traded simultaneously on both NSE and BSE. While this dual-exchange structure promotes competition, it can also lead to pricing anomalies, especially in stocks with low trading volumes.

For highly liquid stocks such as Reliance Industries and HDFC Bank, price differences between exchanges are typically negligible because arbitrage opportunities are quickly eliminated by market participants. However, the situation is different in Small-Cap, micro-cap and SME stocks where trading activity can be sparse on one exchange.

In such cases, the exchange with little or no trading activity may continue to use an outdated last traded price as the basis for its next day's price band calculations. This creates situations where the same stock can trade at noticeably different prices on NSE and BSE.

With more than 5,000 stocks listed on BSE and over 3,200 of them also listed on NSE, a substantial number of smaller companies experience limited trading activity on at least one exchange, making them vulnerable to such pricing distortions.

Impact on Retail Investors

The issue has become increasingly relevant as more retail investors participate in small-cap and thematic investing through direct equity investments, exchange-traded funds and portfolio products.

Consider a stock that closes at Rs 100 on NSE but remains largely inactive on BSE, where the last traded price is Rs 98. If BSE continues to use the older price as a reference, investors may see and transact at prices that do not accurately reflect prevailing market conditions.

Such gaps create opportunities for sophisticated traders to profit through cross-exchange arbitrage while ordinary investors may unknowingly receive less favourable execution prices.

What SEBI Has Proposed

SEBI's consultation paper outlines a straightforward solution. If a stock trades on one exchange but not on another, the inactive exchange would use the active exchange's closing price as the base price for calculating the next day's pre-open session and price band.

The regulator is not proposing a merger of Order Books or a uniform trading system. Instead, it seeks to ensure that both exchanges begin each trading day with the same reference price whenever trading activity is absent on one platform.

This harmonisation would align circuit limits and daily price bands across exchanges, significantly reducing the scope for pricing inconsistencies and arbitrage opportunities.

SEBI has also sought feedback on whether similar treatment should be extended to stocks with extremely low trading activity rather than only those that record no trades during a session.

Expected Benefits

The proposal is expected to deliver multiple benefits across the market ecosystem.

Retail investors could benefit from fairer entry and exit prices, particularly in small-cap and SME stocks where pricing anomalies are more common.

Passive investment products, including small-cap Index Funds and exchange-traded funds, may experience improved tracking efficiency due to more consistent pricing across exchanges.

Liquidity providers and market makers could find it easier to quote prices simultaneously on both exchanges, potentially improving market depth in thinly traded securities.

At the same time, traders who rely on cross-exchange pricing inefficiencies may find fewer opportunities to exploit temporary price gaps.

Part of a Broader Market Reform Agenda

The proposal aligns with SEBI's broader efforts to strengthen India's market structure and improve investor protection. In recent years, the regulator has introduced T+1 settlement, tightened SME IPO regulations, revised derivatives market norms and increased surveillance against market abuse.

Harmonising NSE-BSE price bands represents another step towards improving market quality and operational efficiency. As domestic institutions and foreign portfolio investors collectively manage assets worth more than Rs 100 lakh crore in Indian equities, reducing structural inefficiencies can help enhance confidence in the market ecosystem.

Conclusion

While the proposal may appear technical, its impact could be significant for millions of investors who trade beyond the Nifty 50 universe. By ensuring that both exchanges use a common reference price when trading activity is absent on one platform, SEBI aims to improve transparency, reduce arbitrage opportunities and deliver more consistent execution quality.

For retail investors, the reform could mean that the price displayed on their trading screen is more likely to reflect the actual market value of a stock, regardless of the exchange through which the order is routed. Over time, such improvements can contribute to a more efficient and investor-friendly market environment.

Key Takeaway: SEBI's proposal to harmonise NSE and BSE price bands seeks to eliminate structural pricing gaps in illiquid stocks, improve price discovery and provide fairer execution for retail investors across India's equity markets.

Disclaimer: The article is for informational purposes only and not investment advice.