Pharma major Ranbaxy on Wednesday beat street estimates with a four-fold year-on-year jump in first quarter net profit at Rs 1,247 crore. However, many analysts were unimpressed on the results, which were boosted mainly by forex gains and strong sales of its copy of cholesterol lowering drug Lipitor. The stock was down 1.9% at Rs 503.20 on NSE on Thursday. Net sales of the company owned by Japan’s Daiichi Sankyo surged 73% in Jan-March to Rs 3,695.4 crore. The company launched cholesterol lowering drug Atorvastatin in the US market in December and already has garnered 47% market share, according to its CEO and MD Arun Sawhney. Analysts were expecting it to get around 30% market share. The drug launch helped its US quarterly sales more than double.