Lot size
Also called: lot sizes, market lot
The fixed number of units in one futures or options contract. You trade in whole lots, never in single units.
The exchange sets a lot size for every derivative so that one contract is worth a meaningful amount. Since late 2024 SEBI has required a minimum contract value of about 15 lakh rupees, and the exchanges recalculate lot sizes from average prices every few months.
The Nifty lot was 75 units for most of 2025 and became 65 from the January 2026 expiries. Lot sizes for other indices and single stocks change on the same kind of schedule.
Example
A Nifty option premium is quoted at 120. One lot of 65 costs 120 times 65, or 7,800 rupees. Two lots cost 15,600.
Watch out
Check the current lot size on the exchange website before working out any position. A number from an old article or video can be well out of date.
Learn it properly in
Chapter 1.1: Futures and options in India: how F&O actually works, and why nine in ten retail traders lose