Mumbai, Sept. 2 -- Stockbrokers see revenue fall by up to 20% as the Securities and Exchange Board of India's (Sebi) new closing-price mechanism weighs on futures and options (F&O) trading income, according to industry executives.

Since its 3 August debut, the new framework has wiped out about half of the trading volume and value in Bank Nifty futures, according to a Mint analysis of National Stock Exchange (NSE) data.

As of 31 August, Bank Nifty futures volumes had fallen about 41% to 14,484 contracts, while traded value declined by a similar 41% to Rs.2,512.95 crore. Nifty futures volumes fell 8% to 51,118 contracts, while traded value dropped 9% to Rs.8,056.79 crore.

Since a significant portion of stockbrokers' income is tied to tra...