ISLAMABAD, February 8: Zafar Hijazi, the SECP Chairman, has urged the Pakistan Stock Exchange to fulfill its responsibility as the front line regulator of stockbrokers. The SECP called an emergent meeting with the Board of Directors of PSX yesterday evening to know about the steps that PSX had taken to protect investors of M.R. Securities, a Lahore-based stockbroker who has most recently absconded.