What is a lot size?
Updated 11 October 2026
In the cash market you can buy a single share. Futures and options are different. Each contract covers a fixed quantity of the underlying, called the lot size (or market lot). You can trade one lot, two lots, ten lots, but never half a lot.
Who sets lot sizes
The exchange sets the lot size for each contract, within a framework laid down by SEBI. Every index derivative (on NIFTY, BANKNIFTY and others) and every stock derivative has its own lot. NSE publishes the current lot sizes on its website and in circulars. They change from time to time, so always check the latest list on NSE's website or in your trading app before placing an order. This page deliberately does not quote current numbers, because they go out of date.
Contract value
The key number is not the lot size itself but the contract value:
Contract value = price of the underlying × lot size
This is the full exposure you take with one lot, even though you only put up margin for it.
Worked example
Take a made-up index at 10,000 with a made-up lot size of 200.
- Contract value = 10,000 × 200 = ₹20,00,000
- A 1% move is 100 points. Profit or loss per lot = 100 × 200 = ₹20,000
Now a made-up stock future: Stock ABC at ₹2,500 with a lot size of 300.
- Contract value = ₹2,500 × 300 = ₹7,50,000
- A ₹25 move (1%) = 25 × 300 = ₹7,500 per lot
If the margin for that stock future were, say, 20% of contract value, you would block ₹1,50,000. A 1% move would then be a 5% gain or loss on the money blocked, and a 5% move would be ₹37,500, a quarter of your margin. This is how a small-looking move becomes a large swing in your account.
Why exchanges set minimum contract values
Lot sizes are set so that each contract is large enough to be meaningful and to discourage very small, speculative participation. SEBI sets a minimum contract value for derivatives. In late 2024, as part of measures to curb risk for individual traders, SEBI raised the minimum contract value for index derivatives to ₹15 lakh at the time of introduction. Lots are then fixed so that the contract value stays above the minimum.
Why lot sizes are revised
Prices move, but lot sizes are fixed for a while. If an underlying rises a lot, the contract value of the same lot grows far above the minimum. If it falls, the contract value can slip below. To keep things in range, NSE reviews lot sizes periodically and announces revisions through circulars. A rising price usually leads to a smaller lot; a falling price to a larger one.
NSE's circular spells out which expiries the new lot applies to. Usually existing contracts keep their old lot while newer expiries use the revised one, so for a short time you may see two different lot sizes for the same underlying. If you roll a position from one month to the next, check that your quantity still makes sense.
How lot size affects your risk
- Minimum risk is large. Because you cannot trade less than one lot, the smallest position may already exceed the risk you planned. Work it out with the position size calculator.
- Round down, not up. If your risk budget allows 1.7 lots, the safe answer is 1 lot. See position sizing.
- Options premium is per share. An option quoted at ₹20 on a lot of 200 costs ₹20 × 200 = ₹4,000 per lot to buy, before charges. The option chain shows prices per unit, not per lot; see how to read an option chain.
- Selling options needs full F&O margin, often many times the premium received, because the contract value is large.
Freeze quantity
There is also a maximum quantity per single order, called the freeze quantity, set by the exchange. Orders above it are rejected and must be split. This is separate from the lot size and is also published by NSE.
Risk reminder
Large contract values mean losses can grow quickly. SEBI's studies (2023 and 2025) found about 9 in 10 individual F&O traders lost money in the years studied (SEBI). Before trading any derivative, work out the contract value and what a normal day's move would cost you on one lot.
Questions people ask
- Can I buy less than one lot in F&O?
- No. Futures and options trade only in whole lots. To take a smaller position you would need to use the cash market or a different instrument.
- Where can I find current lot sizes?
- NSE publishes them on its website and in circulars, and your trading app shows the lot size for each contract.
- Why did the lot size change for a contract I trade?
- Exchanges revise lot sizes periodically so contract values stay within the range set by SEBI. Price changes in the underlying are the usual reason.
- How is contract value calculated?
- Multiply the price of the underlying by the lot size. For a futures price of ₹2,500 and a lot of 300, the contract value is ₹7,50,000.