How the ban works
- Each quarter, the exchange sets a market-wide position limit for every stock in the F&O segment.
- Through the day, it monitors the stock's open interest across all futures and options, measured in future-equivalent terms (options counted by their delta).
- When open interest crosses 95% of the limit, the stock goes into the ban from the next session, and the exchange publishes it in the daily ban list.
- While in the ban, only trades that reduce open interest are allowed. Positions that increase it attract a penalty, and brokers block such orders.
- When open interest falls below 80% of the limit, the stock comes out of the ban and normal trading resumes.
A worked example
A stock's MWPL is the equivalent of 4 crore shares.
| Day | Open interest (crore shares) | Share of MWPL | Status |
|---|---|---|---|
| Monday | 3.60 | 90% | Trading as normal |
| Tuesday | 3.85 | 96% | Enters the ban from Wednesday |
| Wednesday | 3.70 | 93% | Still in the ban: not below 80% |
| Thursday | 3.30 | 83% | Still in the ban |
| Friday | 3.15 | 79% | Leaves the ban from Monday |
A trader long 2 lots of the stock's futures on Tuesday can sell them on Wednesday, because that reduces open interest, but cannot buy a third lot or open a new options position. A trader with no position cannot enter one until the ban lifts.
What you can and cannot do during the ban
| Action | Allowed |
|---|---|
| Close or reduce an existing position | Yes |
| Open a new futures or options position | No |
| Add to an existing position | No |
| Roll a position to the next month | Only if the combined trades reduce open interest by the end of the day |
| Trade the stock in the cash market | Yes, the ban applies only to derivatives |
Exchanges charge a penalty on positions that increase open interest during the ban, and brokers pass it on. Most brokers block the orders outright.
How the limit is measured
Under SEBI's framework of 2025, open interest for the limit is counted in future-equivalent terms. A futures lot counts in full; an option counts by its delta, so a far out-of-the-money option adds much less to open interest than an at-the-money one. Intraday monitoring means a stock can be flagged during the session, not only at the close. Each client is also limited to a share of a stock's MWPL across all their positions in it, 10% for most individual clients.
Which stocks go into the ban
Stocks with heavy speculative interest relative to their size: mid-sized companies in the news, stocks with a small free float, and stocks where results or a corporate event have drawn large option volumes. Large stocks rarely reach the limit. The ban list changes daily and is published by NSE before the session.
Why it matters for traders
- Trapped positions. You can close but not adjust: a trader who wants to hedge a position in a banned stock cannot open the hedge.
- Rollovers. Near expiry, a banned stock cannot be rolled freely to the next month.
- Automated strategies. A strategy that trades many stocks should check the ban list before sending entry orders, or the orders are rejected.
- Expiry pressure. Open interest often stays high into expiry, so banned stocks can see sharp moves as positions are forced to close.
F&O ban and physical settlement
Stocks in the ban are often also in the expiry week, when in-the-money positions face delivery margins. A trader who cannot adjust a position because of the ban, and cannot fund delivery, may have the broker close it. See physical settlement meaning.
When the ban matters most
- Expiry week, when open interest peaks.
- Stocks in the news, where speculative positions build quickly.
- Stock option strategies, which should skip banned stocks for new entries.
- Hedged positions, whose hedge leg cannot be opened during a ban.
Related terms
- Physical settlement meaning: delivery of shares at expiry for stock derivatives
- Lot size meaning: the units in one futures or options contract
- Expiry meaning: when contracts settle
- Delta meaning: the weight an option carries in future-equivalent open interest
Learn more
- Stock options trading: how stock options work, including the ban and delivery
- SEBI rules for option trading: position limits and the 2025 framework
- Futures basics: how futures contracts work
Frequently asked questions
What is MWPL?
The market-wide position limit: the most open interest allowed across all traders in one stock's futures and options. It is set each quarter from the stock's free float and delivery value.
Can I trade a stock in the F&O ban?
In the cash market, yes. In futures and options, you can only close or reduce positions until the ban lifts.
How long does the F&O ban last?
Until open interest falls below 80% of the limit. That can be a day or several weeks, depending on how quickly traders close positions.
Does the F&O ban apply to Nifty or Bank Nifty?
No. Index derivatives have their own position limits for large traders but are never placed in the ban.
Where can I see which stocks are in the ban?
NSE publishes the daily ban list before the session, and most brokers show it in their apps. QuantPower's scanner flags banned stocks so strategies skip them.
Sources
- SEBI: circular on market-wide position limits and intraday monitoring for single-stock derivatives, 29 May 2025
- NSE: daily securities in the ban period, and the rules for the ban and its penalties