Sebi approves NSE's expiry day change to Tuesday, BSE to Thursday

🔄 What’s Changing & When

• From September 1, 2025, SEBI has standardized the weekly expiry schedule for equity derivatives:

  • NSE will now expire weekly contracts on Tuesdays, replacing its current Thursday schedule economictimes.indiatimes.com+3newsonair.gov.in+3m.economictimes.com+3business-standard.com+12reuters.com+12m.economictimes.com+12.

  • BSE, which previously used Tuesdays, will shift its expiry to Thursdays newsonair.gov.in+2reuters.com+2livemint.com+2.

• Existing contracts (until August 31, 2025) remain unaffected. Monthly contracts will expire on the last Tuesday (NSE) and last Thursday (BSE) each month m.economictimes.com+3reuters.com+3livemint.com+3.

🎯 Why SEBI Made the Move

• To prevent overlapping expiry days, which can heighten volatility and cause operational issues.

• SEBI’s May circular authorized only two weekly expiry options (Tue or Thu) and set limits on weekly contracts to enhance market stability and investor protection outlookbusiness.com+11m.economictimes.com+11reuters.com+11.

📊 Implications for the Exchanges

🟥 NSE

• Gains a strategic advantage by offering expiry earlier in the week.

• Targets recapturing market share lost to BSE during its Tuesday-weekly run—potentially reclaiming up to 5–10% share in Nifty options volume moneycontrol.com+2livemint.com+2outlookbusiness.com+2.

• Much of its revenue—transaction fees—comes from F&O; this could bolster income .

🟦 BSE

• Could lose volume as some traders may prefer NSE’s new Tuesday expiry.

• Shares have already dropped ~5–6% in early trading, fueled by concerns over displacement in the derivatives market business-standard.com+12reuters.com+12economictimes.indiatimes.com+12.

• Analysts flag potential 19% downside, with key technical resistance around ₹2,924 business-standard.com.

• Motilal Oswal downgraded BSE to Neutral, lowering its target from ₹2,533 to ₹2,300 outlookbusiness.com.

✅ What Traders & Investors Should Watch

1. Volume shifts in weekly Nifty options post-change—NSE uptake vs. BSE decline.

2. BSE stock performance—support/resistance levels and technical signals.

3. Broker sentiment and transaction fee trends (especially NSE revenues).

4. Market reaction to Tuesday expiry timing: will weekend time decay shift behavior? timesofindia.indiatimes.combusiness-standard.commoneycontrol.com

🧭 Strategy Takeaways

• Derivatives traders should reassess trading schedules—expiry day changes may skew volatility and P&L cycles.

• Long-only investors in BSE shares should consider valuation risk; a downtrend below ₹2,500–2,600 could be meaningful.

• Those involved in exchange-traded products or advisory should monitor shifts in open interest and volumes between Tuesday and Thursday sessions.