Mumbai, July 18 -- Securities Exchange Board of India or SEBI, the domestic capital markets regulator has called for a constructive engagement from all stakeholders on the derivatives market amid high investor losses. Speaking at an event organised by the CII in Calcutta, Sebi whole-time member Ananth Narayan G said that there is no question that derivatives and indeed, speculation are vital for price discovery, hedging, and ensuring market depth. But certain trends in our equity derivatives ecosystem have warranted a closer look for a while now as very short - term derivatives dominate our equity derivative volumes. Research has suggested that expiry day option trading increases market volatility and could lead to noise trading that may ...