MWPL
Market-Wide Position Limit — SEBI's aggregate OI ceiling on a stock's F&O contracts that, once 95% breached, freezes new positions and triggers the dreaded ban period.
Definition
MWPL stands for Market-Wide Position Limit, the aggregate cap on total open interest across all futures and options contracts — across all expiries — for a single stock on Indian exchanges. SEBI sets the MWPL at 20% of the free-float market capitalisation of the stock, expressed in shares. NSE and BSE publish each stock's MWPL daily. The MWPL is a single combined limit covering positions held by all participants — retail traders, proprietary desks, foreign portfolio investors, and institutions — collectively. Its purpose is to prevent any single stock's derivative market from becoming so large relative to its underlying equity that settlement or price discovery is compromised.
Why it matters
MWPL matters to active F&O traders because it can abruptly restrict what you can do in a stock you are already trading or planning to trade. When aggregate OI climbs to 95% of the MWPL, NSE places the stock in a ban period: no new positions (long or short, futures or options) are permitted from the next trading session. Only position reduction or squaring off is allowed. The stock exits the ban only when total OI drops back below 80% of the MWPL. Stocks in active momentum phases — those seeing heavy speculative buildup or event-driven OI surges — are the most frequent MWPL breach candidates. A trader planning a multi-week options strategy in such a stock can find themselves unable to adjust legs during the ban, or forced to exit positions at unfavourable prices as other trapped participants rush to reduce exposure simultaneously. NSE publishes a daily ban list; checking it before entering any stock F&O position is basic risk hygiene.
How it works
NSE computes each stock's MWPL as: MWPL (in shares) = 20% × free-float shares outstanding. Free-float excludes promoter holdings, locked-in shares, and strategic stakes. The number is converted to a contract equivalent using the lot size. Throughout the trading day, NSE monitors the aggregate OI in real time. At the end of each session it publishes the OI as a percentage of MWPL for every F&O stock. Stocks crossing 95% appear on the ban list effective the next trading day. Participants who enter new positions in a banned stock are penalised: 1% of the trade value, subject to a floor of Rs 5,000 and ceiling of Rs 1,00,000 per instance, collected by the exchange. The ban lifts automatically once OI falls below 80% of MWPL at the end of a session.
Example
Suppose a hypothetical stock ABC has a free-float of 10 crore shares. Its MWPL is 2 crore shares (20% of 10 crore). With a lot size of 500, the MWPL in contract terms is 40,000 lots. If speculative buying during a corporate event pushes aggregate open interest in ABC futures and options to 38,200 lots — 95.5% of the MWPL — NSE places ABC in the F&O ban list for the next trading day. Traders holding existing positions can only square off or reduce. New long or short positions in any ABC futures or options contract, any expiry, will attract the 1% penalty. Once enough participants close positions and OI falls below 32,000 lots (80% of 40,000), the ban is lifted.
Track OI before it bans you out
TradePulse's open interest data shows OI buildup trends across expiries so you can anticipate MWPL risk before the ban hits.