Markets regulator Sebi's decision to impose stricter regulations in the F&O segment could affect up to 60% of overall F&O trades and approximately 30% of Zerodha's total orders, according to CEO Nithin Kamath. He noted that if traders don't shift from weekly to monthly trades, the impact could be significant. Zerodha has not yet altered its pricing structure and will evaluate the need to increase brokerages once the new regulations take effect on November 20.