SEBI rewrites the F&O playbook

With retail punters crowding “expiry day” trades and index options volumes hitting record highs, the Securities and Exchange Board of India (SEBI) has rolled out the biggest overhaul of equity-derivatives rules since weekly options were born in 2016. 

A 21-page circular issued late evening today (Thursday, May 29, 2025) rewires how open interest is counted, slashes position limits that once looked limitless, and even gifts futures traders their own pre-open price-discovery session. The phased reforms begin on July 1 and run through December, but their impact on brokers’ risk engines and option junkies will be felt immediately.

Why SEBI moved now

Retail participation in index options has surged from 15 per cent of turnover in 2019 to almost 40 per cent today, while same-day “0 DTE” contracts (or zero days to expiration contracts) have become the playground of the Telegram crowd. Regulators worry that one-way speculative deltas can snowball into cash-market stress, especially in thinly traded stocks.

Citing its statutory duty to “protect investors and ensure orderly development,” SEBI convened an expert working group whose recommendations form the spine of Thursday’s circular.

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The big switches

Goodbye raw lots, hello delta-equivalent OI

From now on, every position—futures, calls, puts—will be converted into a Future Equivalent Open Interest (FutEq OI) by applying option delta. A 500-lot long call with a 0.5 delta will count the same as 250 futures longs. Clearing corporations must continue to publish this metric for every scrip so that traders can see risk in apples-to-apples terms.

MWPL tethered to cash-market reality

Market-Wide Position Limits for single-stock contracts drop to the lower of 15 per cent of free-float shares or 65 times the average daily delivery value, subject to a 10 per cent floor. By tying derivatives exposure to delivered cash volume, SEBI hopes to curb “spurious ban periods” that paralyse stocks with puny float.

Ban periods that actually ban

Once a stock breaches 95 per cent of its recalibrated MWPL, traders must shrink—not flip—their net delta by the next day’s close. Adding fresh longs after a stock hits the penalty box will now invite a surveillance penalty.

Caps on index wagers

At the PAN level, an entity’s end-of-day net delta in index options cannot top Rs 1,500 crore, while gross longs or shorts may not exceed Rs 10,000 crore each. In index futures, FPIs, mutual funds, and proprietary desks receive the higher of 15 per cent of the market OI or Rs 500 crore; individuals in the FPI category II receive 5 per cent. A six-month “glide path” (July to December) gives large traders time to bolt on delta-tracking software.

A pre-open for futures

Mirroring the 9:00–9:08 am cash session, current-month stock-and-index futures will gather orders and discover an equilibrium price before the opening bell. During rollover week, next-month contracts join the window to smooth volatility.

Cleaner index construction

Non-benchmark indices that want derivatives must have at least 14 stocks, a max of 20 per cent single-weight and just 45 per cent for the top three, ensuring the contract is not a back-door single-stock bet.

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Timeline at a glance

• July 1, 2025 – Index futures/options caps kick in; delta warning emails by 9 p.m.
• Oct 1, 2025 – New MWPL formula, stricter single-stock ban rules and entity-level limits go live.
• Nov 3, 2025 – Intraday MWPL checks (minimum four random snapshots) and non-benchmark index tests begin.
• Dec 6, 2025 – Pre-open futures sessions and full-strength index-option policing commence.

Industry reaction

Brokers privately welcome the delta-based metric—"It finally aligns margin math with real risk," says the head of risk at a large discount broker—but fret over the technology sprint required before July. Option-writing funds see the Rs 10,000-crore gross cap as workable yet warn that intraday spikes could still trigger margin calls. Retail traders, meanwhile, may find position calculators embedded in app dashboards well before SEBI's December deadline.

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The bigger picture

By stapling derivatives exposure to cash-market depth, SEBI is sending a clear message: speculation is fine, but it must float on real liquidity. The circular also encourages exchanges to manage concentration risk proactively rather than react to it after the fact. Whether the reforms tame expiry-day fireworks or merely shift them to offshore venues will be the litmus test—but for now, India’s Rs 90 lakh crore derivatives bazaar has a new rulebook, and the clock to implementation is already ticking.

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Frequently asked questions

What is SEBI’s new rule for F&O trading in 2025?

SEBI’s 2025 circular introduces sweeping changes to how futures and options (F&O) trading works in India. Key updates include position caps based on delta-adjusted exposure, revised Market-Wide Position Limits (MWPL), stricter rules on ban periods, and a pre-open price discovery session for futures. The changes will be rolled out in phases from July to December 2025.

Why did SEBI change the F&O trading rules?

Retail participation in index options has surged in recent years, with a large number of traders taking speculative positions, especially in contracts expiring the same day. SEBI is concerned that this trend could destabilise the broader market. The new rules aim to curb excessive speculation, improve risk management, and align F&O exposure with actual liquidity in the cash market.

What are the new F&O trading limits for index options?

At the PAN level, a trader’s end-of-day net delta in index options must not exceed Rs 1,500 crore. Additionally, gross long or short positions in index options are capped at Rs 10,000 crore each. These caps aim to prevent excessive leverage and systemic risk.

How do these changes affect retail traders?

Retail traders will need to understand delta-based exposure, as position sizing and risk checks will now use these values. Many brokers are expected to add delta calculators and risk alerts to their platforms to help users comply.

Will this affect option writers or high-frequency traders?

Yes. While the Rs 10,000 crore cap is seen as manageable, large intraday positions might face tighter scrutiny. Algorithmic and proprietary desks will also need to update their systems to track delta exposure in real-time.

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