Announcements

Regulators have updated the way they measure the total exposure (known as Open Interest, or OI) for individual stock derivatives when they are in the ban period.

They are introducing a new, smarter measure called Future Equivalent Open Interest (FutEq OI). This calculation uses a "delta adjustment" to measure the actual risk or exposure in the market more accurately than the old method.

This new rule changes how the Market Wide Position Limits (MWPL) are monitored during the ban period, making the overall system for single stock derivatives more precise and risk aware.

With this change, please note the impact on your F&O stock positions that are or may fall under the Ban period starting Monday, December 8, 2025.

Change in the Open Interest (OI) Calculation methodology - Delta-Based (Future-Equivalent) OI:

Earlier Practice:

Open Interest (OI) was measured based on the total number of outstanding lots / contracts held at the end of a trading day. Market Wide Position Limit (MWPL) Monitoring was only checked at day-end.

New Rule:

Your total exposure is now calculated at the portfolio level, merging your open futures and options positions into one figure called the Future Equivalent Open Interest (FutEq OI). This new method accurately reflects the actual price sensitivity your derivatives positions have to the underlying stock. To enforce the trading limits (MWPL) correctly, the market will now check the Market Wide Position Limit (MWPL) compliance at least four random times during the trading day, instead of just at the end.

How Delta is calculated for Futures & Options:

What will be the impact on your F&O positions in Single Stocks which are in Ban period from December 8, 2025?

If any of the derivative contract enters in Ban Period,

1. Fresh position or roll over will NOT be allowed.

2. You will be allowed to square off your existing positions in the stock in Ban Period. However, if one leg of the hedge position is squared off, it may lead to an increase in FutEqOI. In that case your pending square off orders in that stock will be cancelled and positions will be auto squared off (on best effort basis) any time after 2 PM.

Let's understand with an example:

* In above scenario if the stock has moved into ban period on T+1 day, there are chances that the 5 lots for 24-Feb-2026 may attract penalty, therefore it may result into square off as per risk policy.

The above-mentioned example & figures are hypothetical and intended for the purpose of illustration.

Any breach in delta-based exposure limits on open position in ban period may attract penalties, which may be recovered from clients.

Read the SEBI circular and know more about the complete regulatory framework.