Sensex plunged by 271 points today on weak global cues. The index dropped to 16994 points , when the trade came to close.The National Stock – Nifty – also lost 1.65 per cent to finish at 5,093 points. The state Bank of India dropped 4 points to end at 2,222 rupees.On global front, all the major Asian indices ended in the red and Europe was also trading in the negative zone in mid-session.