The National Stock Exchange (NSE) has announced a revision in the lot sizes for Futures and Options (F&O) contracts on four major indices, effective October 28, 2025. According to the official NSE circular, this update affects the trading lot sizes of Nifty 50, Nifty Bank, Nifty Financial Services, and Nifty Mid Select indices.
Key Revisions in F&O Lot Sizes
Starting October 28, 2025, traders will notice the following changes:
– Nifty 50 : Lot size reduced from 75 to 65
– Nifty Bank : Lot size reduced from 35 to 30
– Nifty Financial Services : Lot size reduced from 65 to 60
– Nifty Mid Select : Lot size reduced from 140 to 120
The Nifty Next 50 Index remains unchanged, with no revision in its F&O lot size.
Implementation Timeline
The current lot sizes will remain in effect until the December 30, 2025 expiry. From that date onward, all newly introduced contracts — quarterly, monthly, or weekly — will be listed with the revised smaller lot sizes.
– The last expiry with existing lot sizes:
– Nifty weekly and monthly contracts : December 23, 2025
– Nifty and Bank Nifty monthly contracts : December 30, 2025
After these dates, all contracts will automatically shift to the revised lot structure.
Why NSE Revises Lot Sizes
The NSE periodically reviews and adjusts lot sizes to ensure contract values remain within a broad, standardized range that aligns with the current market price levels. This adjustment helps maintain a balance between contract value, affordability, and liquidity in the derivative market.
Derivative contracts are leveraged instruments, meaning traders only pay a margin rather than the entire contract value. Since the lot size directly influences exposure and margin requirements, resizing helps prevent contract values from becoming prohibitively expensive as index levels rise.
Impact on Traders and Investors
For retail traders and institutional investors alike, the reduction in F&O lot sizes means lower capital requirements per contract, allowing for greater participation and better risk management. By decreasing exposure per lot, the NSE ensures that its derivatives market remains accessible and efficient.
Market participants must take note of the effective dates and adjust their positions accordingly. As per the circular, members are required to inform clients holding existing or upcoming positions about the transition.
What Traders Should Do
– Review open positions before the expiry dates to align with the upcoming lot size revisions.
– Recalculate margin requirements as per new exposure levels post‑October 28.
– Update trading systems and strategies to account for smaller contract sizes.
The NSE’s decision to reduce F&O lot sizes for Nifty 50 and other major indices aligns with its goal of maintaining balanced contract values and improving participation breadth. With the new lot sizes coming into effect on October 28, 2025, traders should prepare for smoother and more accessible derivative trading conditions.
