NSE Revises Lot Sizes for Key Index Derivatives Like Nifty 50 & Others; Changes Effective from October 28

The National Stock Exchange of India (NSE) has announced a revision in the market lot sizes for derivative contracts across several major indices. This change, detailed in a recent NSE circular, is in line with the Securities and Exchange Board of India's (SEBI) guidelines that call for periodic reviews of lot sizes based on underlying index values. The new lot sizes will come into effect starting October 28, 2025.

NSE Revised Lot Sizes for Key Indices

As per the circular, the changes to the lot sizes are as follows:

Nifty 50: Reduced from 75 to 65

Bank Nifty: Reduced from 35 to 30

Nifty Financial Services: Reduced from 65 to 60

Nifty Mid Select: Reduced from 140 to 120

Nifty Next 50: No change, remains at 25

These revisions aim to align the notional contract value with SEBI's prescribed range, taking into account average index prices observed during September 2025, which were used as the basis for recalculating the lot sizes.

Index Derivative Contracts Implementation Timeline

The updated lot sizes for index derivative contracts will be implemented in a phased manner. For weekly and monthly contracts, the revised lot sizes will take effect starting with the January 2026 expiry.

Meanwhile, for quarterly and half-yearly contracts, the changes will be applicable from December 30, 2025. This gradual rollout is intended to give market participants sufficient time to adjust their trading systems and operational processes accordingly.

Day Spread Order Book Restrictions

In addition to the lot size revisions, NSE has clarified that certain contract combinations will be restricted from accessing the day spread order book. The affected combinations include November 2025 - January 2026, December 2025 - January 2026, and December 2025 - February 2026. Traders and members are advised to take note of these limitations while planning their spread trading strategies.

Guidance for Trading Members

To ensure a smooth transition, NSE has instructed its trading members to proactively inform clients holding open positions in quarterly and half-yearly derivative contracts about the changes in lot sizes. Furthermore, all trading systems and applications must be updated using the latest contract files, which are now available on NSE's extranet server.

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