Closing Auction Chaos: Sensex Swings 1,000 Points in Minutes on Expiry Day
What Happened
The Closing Auction Session (CAS) triggered another bout of extreme volatility on the weekly Sensex F&O expiry. During the final minutes of trading, the Sensex surged from around 74,629 to 75,708, a jump of more than 1,000 points, before reversing nearly 700 points within five minutes. The Nifty 50 also briefly spiked sharply during the indicative close before settling much lower. The sudden move caused some Sensex call options to multiply in value within minutes.
Key Takeaways
The latest episode highlights how the relatively new Closing Auction Session (CAS) is amplifying volatility, especially on derivatives expiry days when liquidity is thinner. Traders witnessed dramatic option price swings, renewing concerns about sharp price distortions and heightened risk during the market's final minutes.