The restriction
SEBI limited weekly expiries to one benchmark index per exchange (NIFTY on NSE, Sensex on BSE). Previously, multiple weekly expiries across indices drove an enormous share of retail options volume.
Why it matters
Weekly expiries were statistically hostile to retail buyers — theta decay and gamma risk near expiry made the payoff profile predatory. Reducing weekly-expiry turnover reduced retail damage.
Effect on volume
F&O turnover dropped after the restriction, particularly in small-lot retail. Professional / institutional volumes were less affected, because they had diversified strategies.
Strategy implications
Strategies that depended on multiple concurrent weekly expiries had to adapt. The Sleeping Trade engine was rebalanced toward single-index weekly and monthly strategies at the same time.