Karachi stock market witnessed bullish trend at the start of a new business week as the benchmark 100 index surged by 243 points on Monday.The business activities started in positive zone in the share market. Buying from foreign investors caused the market to remain in positive zone throughout the day. The KSE-100 index closed at 9280, up 243 points with trade volume of 178 million shares. Bank Alfalah remained volume leader with 3.6 million shares and share price of Rs 14.35, up Rs 0.55.