What Is a Lot in F&O?

Lot size in one line

Lot size is the fixed number of units in one F&O contract. You can buy or sell only whole lots, so the quantity you trade is lots multiplied by lot size. For Nifty 50 the current lot size is 65 units, as listed in the NSE file checked above.

A lot in F&O (futures and options) is the standard quantity represented by a contract. You trade whole lots, so the lot size multiplies the price shown on the screen into a rupee amount. NSE’s lot-size file checked on 15 Oct 2026 lists Nifty at 65 units and Bank Nifty at 30 units for the current contract months. Lot size, premium paid and margin required are different numbers.

One contract, several units

F&O means futures and options. A futures contract creates an obligation linked to an underlying index or share; an option buyer pays a premium for a contractual right. The exchange specifies the quantity bundled into each contract. For an index this is a number of index units; for a stock derivative it is a number of shares.

Buying a lot does not mean buying a single share, and it does not mean buying all the shares in an index. The contract’s multiplier is what turns a price change into money. If the order screen asks for quantity rather than lots, check whether it expects the total units or a contract count before entering a number.

For Nifty at the verified 65-unit lot size, two lots mean 130 units. You cannot place an ordinary F&O order for half of that lot. If a whole lot exceeds your available funds or planned loss amount, a smaller number of units is not available within that same contract.

NSE index lot sizes checked 15 Oct 2026

These figures are a dated reference, not permanent contract terms. Use the exchange file for the exact symbol and expiry you intend to trade. A blank cell in a later-month column does not mean a lot size of zero. It means that file does not provide a size in that cell.

For individual stocks, check the stock’s own row instead of borrowing an index quantity. For a BSE contract such as Sensex, use BSE’s contract information. The lot-size reference tool is a related lookup, while the current exchange contract file is the final check before an order.

An option premium is quoted per unit

Consider this made-up Nifty option example using the verified 65-unit multiplier. Suppose a call costs ₹140 per unit and you buy two lots. Your quantity is 65 x 2 = 130 units. The opening premium is ₹140 x 130 = ₹18,200 before charges. The ₹140 quote is not the cost of the whole position.

Suppose you later sell the same quantity at an invented premium of ₹165. Sale proceeds are ₹165 x 130 = ₹21,450. The gross gain is (₹165 - ₹140) x 130 = ₹3,250. If the premium instead falls to an assumed ₹115, the gross loss is (₹140 - ₹115) x 130 = ₹3,250. Brokerage and other applicable charges alter the final result.

For those two lots, a ₹1 change in the option’s premium changes the position value by ₹130. A point gained or lost in the Nifty index does not necessarily change the option premium by ₹1. Option prices also respond to time remaining and changing expected volatility. Keep the option premium and underlying index level separate in your notes.

For a bought option, the premium is the money paid for the option right. Selling an option produces a premium receipt together with an obligation. That receipt alone is not the seller’s final profit. Expiry handling and any resulting stock position need separate attention. The Nifty options premium calculator helps translate a per-unit premium into a position amount.

Contract value: what one lot is really worth

Contract value (also called notional value) is the price of the underlying multiplied by the lot size. It tells you how much market exposure one lot carries. It is not what you pay to enter the trade.

Take a made-up Nifty futures price of 25,000. One lot is 25,000 x 65 = Rs 16,25,000. For a stock future at an assumed price of Rs 500 with a lot of 400 shares, contract value is 500 x 400 = Rs 2,00,000. Both prices and the stock lot here are invented to show the sum.

The same lot size also tells you your profit or loss for each point or rupee move. With 65 units, a 1-point move in the Nifty future is worth Rs 65 per lot (1 x 65), and a 10-point move is Rs 650. With 2 lots (130 units) a 1-point move is Rs 130. This is the quickest way to size a stop in rupees.

Futures value and futures margin are different

In a separate fictional futures example, assume a Nifty futures entry price of 25,000 and one lot of 65 units. The contract’s notional value, meaning its full price-linked value, is 25,000 x 65 = ₹16,25,000. This is not a quote for how much margin your broker will collect.

If that futures price rises to an assumed 25,100 and you close the long position, the price change is 100 points. Gross profit is (25,100 - 25,000) x 65 = ₹6,500. A fall to an invented 24,900 instead gives a gross loss of ₹6,500. A short futures position reverses the profit and loss direction for the same price movement.

NSE Clearing uses a portfolio-based margin system, with parameters specified from time to time. Margin is security against obligations; it is not the contract’s purchase price and is not a cap on losses. Do not calculate a current margin requirement by copying an old percentage from an article. Check your broker’s requirement for the actual contract and the rest of your open positions.

The futures margin calculator can help explore entered assumptions. It cannot replace the amount required for a real order. Your remaining funds must also cover changing obligations and costs, rather than assuming the opening margin is the only cash that can be needed.

Lot size vs contract value vs margin vs exposure

People often mix these up. Margin is the smallest of the four numbers, but it does not cap your loss. Exposure is what moves your account, and lot size is the building block for both.

Why two expiry months can need different checks

A lot belongs to a contract with a particular expiry. A revision can leave older and newly introduced contracts with different quantities during the transition. Long-dated contracts can have a separate conversion date. Avoid the blanket assumption that every expiry always shares the quantity you traded last month.

For example, NSE circular NSE/FAOP/70616, dated 3 Oct 2025, set out revised index lots and an expiry-specific transition. Existing weekly and monthly contracts through the December 2025 expiry retained their old sizes; existing quarterly and half-yearly contracts had a specified end-of-day conversion. That historical transition is why the latest file and the intended expiry matter more than a remembered headline.

A change in quantity also changes the meaning of a rule written only as “trade a lot.” Write the total units and the planned rupee loss alongside the lot count. The position-sizing guide explains how to connect quantity with a planned exit distance.

Who sets lot sizes and why they change

The exchanges (NSE and BSE) set lot sizes, following rules from SEBI, the market regulator. SEBI's circular SEBI/HO/MRD/TPD-1/P/CIR/2024/132, dated 1 Oct 2024, says a new index derivative contract must have a value of at least Rs 15 lakh when it is introduced, and that lot sizes are set so that contract value stays between Rs 15 lakh and Rs 20 lakh at review. Under that circular Nifty 50 moved from 25 to 75 units for new contracts from Nov 2024.

When an index rises a lot, one lot becomes worth more than the band allows, so the exchange cuts the lot size. When it falls a lot, the exchange can raise it. That is why the number in an old article or an old trade of yours may not match today. Use the exchange file for the expiry you plan to trade.

Why you cannot trade half a lot

Exchange contracts are standardised. Everyone trading that contract trades the same unit, which is what allows orders to match. So an order must be one lot or a whole multiple. If a single lot is too big for your risk limit, the answer is a smaller contract or a defined-risk position such as an option you buy, not half a lot.

There is also a maximum per order, called the freeze quantity. An order above it is rejected, and large traders split orders into pieces. See the freeze quantity page.

Where to check today's lot size

• The NSE permitted lot sizes file (fo_mktlots.csv) lists every index and stock contract by month.
• For BSE contracts such as Sensex, use BSE's contract information.
• The OneTradeJournal lot size reference table and F&O lot size and expiry calendar collect the latest sizes in one place, and the F&O lot sizes explained guide covers the history.
• Your broker's order screen shows the lot size for the contract you pick. Cross-check it against the exchange file before a large order.

The journal does not fill a quantity for you. Enter the lots and units yourself so that the figure matches the contract you traded.

How much money do you need for one lot of Nifty options?

To buy an option you pay the premium times the lot size. At an assumed premium of Rs 140, one lot costs 140 x 65 = Rs 9,100 plus charges. To sell an option or hold a future you need margin, which depends on the contract and your other positions. See the futures margin calculator and the F&O margin requirements guide, and then check the figure your broker shows.

The quantity can matter at settlement too

An open stock derivative can lead to delivery of the full share quantity. NSE’s physical-settlement circular confirms mandatory physical settlement of stock derivatives from the October 2019 expiry onward. For a stock position, understand the funds or shares that settlement can require; the option premium shown at entry is not a complete delivery budget.

Before carrying a stock contract toward expiry, confirm the contract terms, your broker’s delivery process and the applicable deadlines. A journal can preserve the intended exit and the actual result, but it cannot close an order or satisfy a delivery obligation for you.

Questions beginners ask about lots

Sources

• NSE: permitted market lots, checked 15 Oct 2026.
• NSE: Nifty contract size specifications, checked 15 Oct 2026.
• NSE/FAOP/70616: index lot revision and transition dates, checked 15 Oct 2026.
• NSE Clearing: portfolio margin system, checked 15 Oct 2026.
• NSE/INSP/47293: physical settlement of stock derivatives, checked 15 Oct 2026.