Securities and Exchange Board of India (Sebi) Chairman Tuhin Kanta Pandey on Friday said the regulator is working on developing longer-term futures and options (F&O) contracts in the equity derivatives market as part of its broader effort to strengthen the derivatives ecosystem. Speaking at the ET Now Market Summit in Mumbai, Pandey said deepening the cash market remains a priority for Sebi. The regulator is reviewing the lending, borrowing and short-selling framework to improve inter-linkages between the cash and derivatives markets and enhance liquidity.