Introductory Context
"Options trade in standardised lots, not individual units. Lot size determines the minimum trade size and your actual premium cost. Nifty 50: 75 units per lot. Bank Nifty: 30 units. FinNifty: 65 units. Midcap Nifty: 50 units. Stock options: varies by stock. Always verify on NSE before trading. "
Why Lot Sizes Exist
Exchanges standardise derivatives contracts to create liquidity. Every Nifty futures or options contract has identical specifications for all participants — same quantity (lot size), same expiry structure, same strike intervals. This standardisation means any buyer can transact with any seller, creating the deep liquidity that makes tight bid-ask spreads possible. The lot is the atomic unit of options trading — you cannot buy half a lot or 40 units. You buy 75 (one lot) or 150 (two lots) or 225 (three lots).
Current Lot Sizes — Post-November 2024 SEBI Revision
SEBI revised lot sizes significantly in November 2024, increasing the minimum contract value across all major index options to between ₹15 lakh and ₹20 lakh per contract. This was a deliberate regulatory intervention to reduce participation by under-capitalised retail traders.
Current Lot Sizes — Verify Before Every Trade
Nifty 50: 75 units per lot. Bank Nifty: 30 units per lot. FinNifty: 65 units per lot. Midcap Nifty: 50 units per lot. Stock options: varies by stock (typically 500–5,000 units). SEBI revises lot sizes periodically. Always verify the current lot size on nseindia.com under Equity Derivatives → Contract Specifications before placing any trade. Never rely on memory or older educational resources.
Calculating Total Cost — The Multiplication That Changes Everything
Total cost = premium per unit × lot size. Working through all four index options with a realistic ATM premium:
• ₹120 × 75 = ₹9,000 per lot: Nifty 50 CE at ₹120.
• ₹200 × 30 = ₹6,000 per lot: Bank Nifty CE at ₹200.
• ₹85 × 65 = ₹5,525 per lot: FinNifty CE at ₹85.
• ₹150 × 50 = ₹7,500 per lot: Midcap Nifty CE at ₹150.
A trader who sees 'Nifty CE premium ₹80' and thinks they are making an ₹80 commitment has made an error — they are committing ₹6,000. Calculate total cost before every order, without exception.
Lot Size and Maximum Loss
Since the maximum loss for an option buyer is the total premium paid, lot size directly determines maximum loss per position. If you buy 3 lots of a Nifty option at ₹120 premium: maximum loss = ₹120 × 75 × 3 = ₹27,000. The lot count is the most direct lever for controlling risk per trade — adding lots increases both potential gain and maximum loss proportionally.
Calculate Total Cost Before Confirming
Before every options order: Total Cost = Premium × Lot Size × Number of Lots. Does this total cost fit within your 2% risk rule? On a ₹4 lakh trading account, maximum risk per trade = ₹8,000. At ₹120 premium, 1 lot of Nifty costs ₹9,000 — slightly above your limit. Either choose a slightly OTM strike with lower premium, or accept that current Nifty lot sizes require a minimum account of approximately ₹5–6 lakh for proper single-lot position sizing.
Stock Option Lot Sizes — A Different World
Stock options lot sizes vary significantly by stock, set by SEBI to ensure each contract has a minimum notional value. Because stock prices vary enormously — from ₹50 to ₹8,000+ — lot sizes must vary inversely to maintain consistent contract value.
Example lot sizes (these change with SEBI reviews — verify on NSE):
• 500 shares per lot Reliance Industries:
• 550 shares per lot HDFC Bank:
• 400 shares per lot Infosys:
• 150 shares per lot TCS:
Physical Settlement Capital Requirement
For stock options, lot size has an additional critical implication at expiry: if your stock call expires ITM and you hold it to expiry, you must purchase lot size × number of lots of the underlying shares at the strike price. For 2 lots of an HDFC Bank 1,800 CE (550 units per lot): you must purchase 1,100 shares at ₹1,800 = ₹19.8 lakh. This is why exiting stock options before expiry is non-negotiable for retail traders without this capital available.
Physical Settlement Risk
Holding an ITM stock option to expiry requires capital far beyond the premium paid — potentially ₹10–20 lakh for a position that initially cost ₹10,000–₹20,000 in premium. Brokers will auto close your position if you do not have the capital, often at the worst possible execution prices. Always exit stock options before expiry.