Lot Size
The fixed number of underlying units bundled into one F&O contract, set by the exchange rather than the trader.
Indian index options can't be bought or sold per-share the way equity delivery can. Every order is in whole lots. The exchange periodically revises lot sizes to keep a contract's notional value inside SEBI's mandated band, which is why lot sizes have changed more than once for NIFTY, BANKNIFTY and FINNIFTY over the years. Always check the current lot size before sizing a position; a stale number from an old screenshot or an outdated blog post is an easy way to over- or under-size a trade.
Because margin, brokerage and even STT are all calculated per lot rather than per share, lot size is the unit every other cost and risk figure on a position is built from, and getting it wrong cascades through every downstream calculation.
Example: at a lot size of 65, a 10-point move in NIFTY is worth ₹650 to a single-lot position, not ₹10. The lot size is the multiplier that turns an index-point move into a rupee P&L, and it's the first number that goes into sizing any trade correctly.
Frequently asked
Where can I find the current lot size of each index?
Each index has its own DeltaK page: NIFTY 50, Bank Nifty, FinNifty, Midcap Nifty, Sensex and Bankex. Each reads the lot size from the exchange's contract list every six hours and prints the date it was read, along with the freeze quantity and the expiry day.
How is lot size different from freeze quantity?
Lot size is the smallest tradeable unit, the multiplier on a single contract. Freeze quantity is the largest number of units the exchange accepts in one order. Lot size sets your floor; freeze quantity sets your ceiling per order.
Why do F&O lot sizes keep changing?
SEBI requires each contract's notional value to sit inside a mandated band. As an index level rises or falls, the exchange revises the lot size by circular to bring notional value back into that band. That is why a lot size quoted in an older article is often no longer the live figure.
By index
The current lot size, expiry day and freeze quantity for each, read from the exchange's contract list.
Every NSE F&O share's lot size, A to ZRelated terms
See it read live, not just diagrammed
DeltaK reads Aegis/Zenith wall migration and RRG rotation live across NIFTY, BANKNIFTY, FINNIFTY and MIDCPNIFTY. Sign in and watch it work in Paper mode.