SEBI Likely to Restore 30-Minute VWAP for Derivatives Settlement While Retaining Closing Auctions for Less-Liquid Stocks, Sources Say

Update — 05 Oct 2026, 22:03 IST

# SEBI Likely to Restore 30-Minute VWAP for Derivatives Settlement While Retaining Closing Auctions for Less-Liquid Stocks, Sources Say

Finin2min 2-minute summary

SEBI’s closing-auction experiment may be split into two tracks. Reuters reports that the regulator is likely to stop using the closing auction to calculate derivatives settlement prices for at least a year and instead use the volume-weighted average price from the final 30 minutes of trading. Closing auctions would still be used to set end-of-day prices for less-liquid cash-market stocks. The report is based on sources with direct knowledge; SEBI had not issued the final rule at the research cutoff. That means Finin2min treats this as a significant likely policy direction, not an operative circular yet.

**Last verified:** 5 October 2026, 5:40 PM IST

Key verified facts

• Reuters sources say SEBI is likely to use the last 30 minutes’ VWAP for derivatives settlement for at least a year.
• Closing auctions are expected to remain for less-liquid cash-market stocks.
• Reuters says implementation is expected by the end of October.
• SEBI had already opened a public consultation on 12 September after announcing the review on 3 September.
• No final operative SEBI circular confirming the Reuters-reported solution was published at the research cutoff.

How the problem developed

SEBI introduced the Closing Auction Session in August for stocks linked to futures and options. A short end-of-day auction was meant to improve closing-price discovery and bring India closer to practices used in other major markets.

But expiry sessions produced sharp indicative swings and large option-price moves. SEBI publicly announced a review on 3 September and then issued a consultation paper on 12 September covering CAS, market timings and derivatives settlement methodology.

What Reuters says is now likely

Two sources told Reuters that SEBI is expected to use the last 30 minutes’ volume-weighted average price, or VWAP, for derivative pricing. The closing auction would continue for less-liquid stocks in the cash market. The regulator is also expected to keep the broad trading timetable, with normal cash trading until 3:30 p.m. and derivatives trading until 3:45 p.m.

Reuters says implementation is expected by the end of October, but that timing is still source-reported.

Why VWAP can reduce single-window distortion

A closing auction concentrates price discovery into a short period. That can work well when liquidity is deep, but a thin or imbalanced auction can produce a closing price that differs sharply from the preceding continuous market.

A 30-minute VWAP spreads the settlement calculation across many trades. One unusually high or low print has less influence because each trade is weighted by volume. That can make expiry settlement harder to distort through a brief end-of-day imbalance, although no methodology eliminates all market risk.

Simple derivatives example

Assume an index option settles based on an underlying price of 25,000. If an auction temporarily pushes the closing value to 24,700, a put option near the strike can gain substantial intrinsic value even if the index traded around 25,000 for most of the session. If settlement instead uses a 30-minute VWAP of 24,980, the payoff can be very different.

That is why settlement methodology is not a technical detail; it directly changes cash flows between derivative buyers and sellers.

Why CAS may remain for some cash stocks

SEBI’s apparent compromise recognises that the goals are different. Cash-market closing auctions can help form a representative closing price for securities where continuous-market closing prints may be thin. Derivatives settlement, however, may need a benchmark that is robust against short-lived auction volatility because large contract payoffs depend on it.

Keeping CAS for selected cash stocks while using VWAP for derivative settlement would separate these two objectives.

What is not final

There was no final SEBI circular implementing the reported change at the research cutoff. The official public record still includes the September review release and consultation paper. Broker risk engines, exchange systems and legal compliance should therefore wait for the operative circular and exchange implementation notices.

The reported 20,000 consultation suggestions also should not be converted into a claim that every respondent supported the same solution.

What to watch next

The decisive document will be SEBI’s final circular, followed by exchange notices specifying the effective date, settlement formula and any transition rules. Finin2min should update this same canonical when that primary source appears and then remove source-reporting qualifiers only to the extent the official text confirms them.

Who is affected

Futures and options traders, brokers, exchanges, clearing corporations, passive funds, institutional desks, index users and risk teams that rely on closing and settlement prices.

Practical action / control point

Update the existing canonical but keep the change labelled likely/source-reported until SEBI issues the final circular. Traders and systems teams should not change production settlement logic solely on the Reuters report.

Finin2min bottom line

Derivative settlement prices directly affect expiry payoffs. Separating the cash-market closing mechanism from derivative settlement can reduce extreme expiry distortions while preserving SEBI’s broader price-discovery experiment.

Source & methodology

• *Controlling source:** Reuters exclusive, supported by SEBI’s 12 September consultation paper and 3 September review release
• *Source URL:** https://www.reuters.com/world/india-markets-regulator-partly-reverse-derivative-settlement-rules-after-2026-10-05/
• *Source reference:** Reuters exclusive 5 Oct 2026; SEBI consultation 12 Sep 2026 remains the latest public primary framework at cutoff
• *Source date:** 2026-10-05

• *Supporting primary/context sources:**
• https://www.sebi.gov.in/reports-and-statistics/reports/sep-2026/consultation-paper-on-review-of-certain-aspects-of-the-closing-auction-session-market-timings-and-settlement-methodologies-for-derivative-contracts-_104464.html
• https://www.sebi.gov.in/media-and-notifications/press-releases/sep-2026/sebi-to-review-settlement-price-methodology-for-derivative-contracts-in-the-light-of-cas-rollout_104260.html

Reader note

This FinNews explainer reports the status as of 5 October 2026, 5:40 PM IST. It is general information for readers following sebi and should not replace transaction-specific investment, tax, legal or treasury advice.

# Closing Auction Volatility Flips Direction: Nifty and Sensex Indicative Levels Jump More Than 1% Before Modest Final Gains

Finin2min 2-minute summary

India’s closing-auction volatility reappeared on September 10, this time with indicative benchmark levels briefly jumping more than 1% after slight losses at the normal session close.

What changed

Indicative Nifty and Sensex closing levels briefly rose more than 1% during CAS after slight losses at the end of normal trading.

Why it matters

Repeated large indicative moves in both directions strengthen the case for reviewing how liquidity, expiry-day positioning and final-price formation interact in CAS. Closing prices affect benchmarks, derivatives settlement, passive execution and valuation.

Who is affected

Investors, finance teams, businesses, regulators, professionals and other stakeholders whose costs, revenues, compliance obligations, funding, market exposure or strategic decisions are connected with this development.

Action / control point

Preserve the existing CAS/settlement-review canonical and await any formal SEBI/NSE consultation, circular or methodology change before describing a regulatory fix as decided.

Key verified facts

• Indicative Nifty and Sensex closing levels briefly rose more than 1% during CAS after slight losses at the end of normal trading.
• Final gains were much smaller: Nifty +0.20% and Sensex +0.19%.
• Reuters said CAS has amplified last-minute swings because liquidity is thinner during the auction.
• Sensex weekly derivatives expiry was an additional source of expected volatility.
• This September 10 event is market evidence; it is not a new SEBI rule or final regulatory conclusion.

Finin2min analysis

The first control is to separate the **verified event** from its possible consequences. The event facts above come from the controlling source identified below. Market impact, commercial implications and forward-looking outcomes can change as new filings, prices, orders or regulatory text emerge.

For finance teams, the practical questions are whether the development changes cash flow, funding cost, liquidity, foreign-exchange exposure, commodity sensitivity, margins, provisioning, valuation assumptions, covenant headroom or capital allocation. An announced target, proposed policy, filing, interview statement or intraday price is not automatically realised revenue, legally operative expenditure or a final liability.

For legal and regulatory readers, status matters. A consultation, court hearing, source-based report, filing milestone or stated policy objective carries a different evidentiary weight from a notified rule, signed contract, final judgment or official auction result. Finin2min therefore preserves those distinctions rather than converting a strong headline into a stronger legal claim.

What to watch next

• SEBI discussion/consultation paper
• NSE/BSE implementation clarifications
• CAS depth and participation
• Expiry-day closing-price dispersion

Source and methodology

- Controlling source: Reuters — https://www.reuters.com/world/india/indian-shares-open-muted-mideast-conflict-keeps-oil-above-100-2026-09-10/

- Source date: 2026-09-10

Finin2min uses a primary-source-first hierarchy. Official regulator, government, court and company documents control legal and operative facts where available. Reuters is used for time-sensitive market prices, interviews and source-based developments when it is the strongest accessible verified source. Competitor finance portals are not used as controlling sources in this READY batch.

Disclaimer

This material is for information and education only. It is not investment, legal, tax or financial advice. Markets, regulations, litigation, transaction terms and source-reported expectations can change after the stated cut-off. Verify the latest controlling source and obtain appropriate professional advice before acting on a material decision.