New Delhi, Sept. 18 -- Proprietary traders' share of equity options trading on the National Stock Exchange (NSE) fell to the lowest in 22 months in August, underscoring the impact of central bank's tighter bank funding norms and the closing auction session (CAS) introduced in the cash market.

Their combined share of index and stock options fell by 62 basis points to 47.3% in August from July, its lowest level since November 2024, when it stood at 47.1%, according to the NSE's latest Market Pulse data. A basis point is one-hundredth of a percentage point.

The BSE does not provide a similar breakdown of participant shares. However, analysts said proprietary trading activity in BSE options would also have been affected by the funding norms...