Sensex Expiry Day: BSE Weekly Schedule, Expiry Rules and NSE Comparison

Sensex expiry day is now every Thursday on BSE. This is the result of a major restructuring of index derivative expiry schedules implemented by NSE and BSE in August and September 2025.

When Is Sensex Expiry Day?

Sensex weekly options expire every Thursday on BSE. Monthly Sensex expiry falls on the last Thursday of each month. Bankex and Sensex 50 monthly expiries also fall on the last Thursday.

If Thursday is a market holiday, expiry shifts to the previous trading day.

This schedule took effect on September 4, 2025. Before that date, Sensex weekly options expired on Tuesday. BSE moved the expiry to Thursday as part of a coordinated restructuring with NSE, which simultaneously moved Nifty 50 expiry from Thursday to Tuesday.

What Changed: NSE and BSE Expiry Restructuring

In August and September 2025, both exchanges overhauled their derivatives expiry schedules to distribute trading activity across different days of the week:

NSE changes (effective September 2, 2025):

• Nifty 50 weekly expiry: moved from Thursday to Tuesday
• Bank Nifty monthly expiry: moved to last Wednesday
• FINNIFTY and MIDCPNIFTY expiries retained on their respective days

BSE changes (effective September 4, 2025):

• Sensex weekly expiry: moved from Tuesday to Thursday
• Bankex and Sensex 50 monthly expiries moved to last Thursday

Full Index Expiry Calendar (Post-September 2025)

BSE Expiry Day vs NSE Expiry Day: Key Differences

The Sensex derivatives market is substantially smaller than the Nifty derivatives market. Daily turnover on BSE Sensex expiry days averages ₹10,000–₹15,000 crore, compared to ₹2.5–₹3 lakh crore on NSE Nifty expiry days. Liquidity is an important consideration for traders choosing between BSE and NSE index derivatives.

How Sensex Expiry Day Works

Sensex expiry day follows the same settlement mechanics as NSE expiry days:

• Final settlement price is based on the average Sensex value during the last 30 minutes of trading (3:00 PM to 3:30 PM IST)
• In-the-money options receive automatic cash settlement at their intrinsic value against the final settlement price
• Out-of-the-money options expire worthless — buyers lose the full premium paid
• No manual position closure is required; settlement is automatic

Why Did BSE Move Sensex Expiry to Thursday?

The objective of the restructuring was to reduce derivatives market congestion. Previously, NSE concentrated significant volume on Thursday (Nifty expiry) and BSE had Sensex expiry on Tuesday. The new schedule distributes expiry activity across Monday, Tuesday, Wednesday, and Thursday — creating distinct liquidity windows for each index.

Analysts projected the schedule change would narrow BSE's market share in index options from approximately 24% to 21%, while NSE would gain additional turnover. The Thursday window for Sensex creates a distinct two-day activity cycle (Wednesday–Thursday) separate from NSE's primary Tuesday expiry cycle.

Sensex Expiry Day for Traders

The same dynamics that apply on NSE expiry days also apply on BSE Sensex expiry day:

• Time decay accelerates sharply on Thursday for near-expiry Sensex options
• Open interest in near-expiry Sensex contracts falls rapidly through the session
• Intraday volatility in Sensex is typically elevated relative to non-expiry sessions

The lower liquidity on BSE compared to NSE means bid-ask spreads on Sensex options can be wider, particularly for strikes further from the money. Traders should factor liquidity into position sizing on BSE expiry day.