NISM-Series-VIII: Equity Derivatives · Trading Mechanism

Position Limits and Trading Limits in Equity Derivatives

Updated 11 October 2026

Position limits cap how large an open derivatives position a client, a trading member or the whole market can hold in a stock or index. The MWPL is the market-wide cap on a stock. When open interest crosses 95% of MWPL, the stock enters a ban period, and you can only reduce positions.

Understand Position Limits and Trading Limits

A position limit is a ceiling on the open positions one participant can hold. Regulators set limits so that no one can dominate a contract, distort prices or create risk that the clearing corporation cannot handle.

Limits work at three levels. The client-level limit applies to each individual client or group of clients acting together. The trading member-level limit applies to the positions of a member across all its clients. The market-wide position limit (MWPL) applies to the total open interest in a single stock across all participants and all exchanges.

For stock derivatives, the client-level limit is the higher of 1% of the free-float market capitalisation (counted in number of shares) or 5% of the open interest in all derivative contracts on the stock. MWPL is set at 20% of the free-float number of shares, that is, the shares held by non-promoters, so a larger free float gives a larger MWPL. For the trading member-level limit, use the figure given in the current NISM workbook.

The exchange monitors MWPL every day. When the combined open interest across all derivatives contracts on the stock crosses 95% of MWPL, the stock enters the ban period. During the ban you may only trade to reduce or close existing positions. New positions that raise open interest attract penalties. The ban ends only when open interest falls to 80% of MWPL or below.

Trading and exposure limits are different. They are controls on how much a member or client can trade, set from the margin and capital deposited. Position limits are about the size of open positions. Index derivatives also have limits, set in rupee terms and revised by SEBI from time to time, so check the latest workbook figures.

Key formulas to remember

Client-level limit (stock derivatives): Higher of 1% of free-float shares OR 5% of open interest in all derivative contracts on the stock; The word is 'higher'. The limit is counted in number of shares.
MWPL (stock derivatives): MWPL = 20% of the free-float number of shares (shares held by non-promoters); A larger free float gives a larger MWPL.
Ban period entry: Combined open interest across all derivatives contracts on the stock > 95% of MWPL; Open interest is counted across all exchanges.
Ban period exit: Open interest ≤ 80% of MWPL; Falling just below 95% does not lift the ban.
During ban: Only trades that reduce open positions are allowed; Fresh positions attract penalties.

How to solve Position Limits and Trading Limits questions

Use this order for any position limit question. It stops you mixing up the three levels.

1Identify the level asked: client, trading member or market-wide.
2Note whether the instrument is a stock or an index. Stock rules carry the formulas you need to remember.
3Pick the right rule: higher of two tests for clients, the current workbook figure for members, percentage of MWPL for the ban.
4Convert everything to the same unit, either shares or rupees, before comparing.
5Calculate each test separately, then apply 'higher' as the client rule says.
6For ban questions, compare open interest with 95% to enter and 80% to exit, and check which stage the stock is in.
7Check that your answer fits the situation: a ban means reduce-only trading.

Quickest way: Three-number memory method

When to use it: Use it for direct recall MCQs where you must choose between look-alike options.

Remember 95 and 80: ban starts above 95% of MWPL, ends at 80% or below.
Remember the client rule: higher of 1% of free-float shares or 5% of open interest. For member-level limits, rely on the current workbook figure, not a memory trick.
If an option says the ban ends as soon as open interest drops below 95%, reject it.
If the stem says ban period, the only permitted trades are those that reduce positions.

Common mistakes in Position Limits and Trading Limits

Applying 'lower of' to the client-level limit.
Students assume a limit should be the tighter, smaller number, or confuse it with other rules.
Fix: The client-level limit for stock derivatives is the higher of the two tests. Calculate both, then pick the larger.
Thinking the ban lifts when open interest falls under 95% of MWPL.
Students assume the exit level equals the entry level.
Fix: The ban ends only at 80% of MWPL or below. Between 80% and 95% an already banned stock stays banned.
Believing new positions are allowed in the ban period if they are hedged.
The idea of hedging sounds safe, so students allow it.
Fix: In the ban period only trades that reduce open positions are allowed. Anything that adds to open interest draws penalties.
Counting open interest on one exchange only.
Students think of NSE in isolation.
Fix: MWPL is measured on the combined open interest across all exchanges for that stock.
Mixing position limits with trading or exposure limits.
Both use the word 'limit'.
Fix: Position limits cap open position size by level. Trading and exposure limits depend on margin and capital, and control how much a member or client can trade.
Comparing shares with rupees directly.
Stock client limits are in shares, while some other limits are stated in rupees.
Fix: Convert to one unit first, using the stock price, before you compare.

Worked examples

Example 1

A stock has 20 crore free-float shares. Total open interest in its derivatives is 1.2 crore shares. What is the client-level position limit?

Show the solution

Test 1: 1% of free-float shares = 1% × 20 crore = 20 lakh shares.
Test 2: 5% of open interest = 5% × 1.2 crore = 6 lakh shares.
The client-level limit is the higher of the two.
Higher of 20 lakh and 6 lakh is 20 lakh.

Answer: 20 lakh shares

Example 2

A stock has an MWPL of 10 crore shares. Its combined open interest rises to 9.6 crore shares and the stock enters the ban period. Open interest later falls to 8.5 crore shares. Can a client create a fresh long position at that point?

Show the solution

Entry test: 95% of 10 crore = 9.5 crore. Open interest of 9.6 crore is above it, so the ban applies.
Exit test: 80% of 10 crore = 8 crore. The ban ends only when open interest is 8 crore or lower.
At 8.5 crore, open interest is still above 8 crore, so the ban continues.
In the ban period only trades that reduce open positions are allowed.

Answer: No. The ban continues because open interest of 8.5 crore is above 80% of MWPL (8 crore). Only position-reducing trades are allowed.

Exam tips

Expect direct recall of 95% and 80%. Memorise both numbers and which one starts and which one ends the ban.
Read 'higher' carefully. The client-level stock limit is the higher of the two tests, and trap options say 'lower'.
Calculation questions are short: two percentages and one comparison. Do the arithmetic in shares and keep units consistent.
Questions on trading limits versus position limits test the difference in purpose. Position limits cap open positions. Trading and exposure limits are tied to margin and capital.
Index limits are revised by SEBI, so for index figures and member-level limits go by the current NISM workbook rather than older notes.

Practice questions from Trading Mechanism

Position Limits and Trading Limits: frequently asked questions

What is MWPL in equity derivatives?

MWPL is the market-wide position limit for a stock. It caps the total open interest in that stock's derivatives across all participants and exchanges. It is set at 20% of the free-float number of shares, that is, the shares held by non-promoters.

What happens when a stock goes into the ban period?

The combined open interest across all derivatives contracts on the stock has crossed 95% of MWPL. From then on you can only trade to reduce or close existing positions. Creating fresh positions attracts penalties.

When does the ban period end?

It ends when combined open interest falls to 80% of MWPL or below. A fall to just under 95% is not enough.

What is the difference between client-level and member-level position limits?

The client-level limit applies to a single client or group acting together. For stock derivatives it is the higher of 1% of free-float shares or 5% of open interest. The member-level limit applies to all of a member's positions, and you should take its exact figure from the current NISM workbook.