The Sensex witnessed frenzied buying in the first four trading days of the week. The index gained almost 600 points from its intra-week low of 10,109 on Monday (February 27). A "No Surprise" Budget on February 28, coupled with heavy buying by foreign institutional investors (FIIs), saw the Sensex zoom past the 10,700-mark to touch a high of 10,706 on March 2. Selective profit-taking on Friday (March 3) saw the Sensex pare some gains, but still finished the week with a solid gain of 3.7% (394 points) at 10,595.Bharti Tele, ITC and Tata Motors were the major contributors to the Sensex upmove adding 50, 47 and 45 points, respectively. On the other hand, HDFC (taking away 16 points) and ONGC (10 points) were the notable draggers.Maruti zoomed over 19% (Rs 152) to Rs 928, and was the top gainer among the Sensex stocks this week. Tata Motors, ACC, Bharti, BHEL and Grasim gained 10-15% each.HDFC dropped 3.3% to Rs 1,318 and ONGC slipped 2.5% during the week.Educomp Solutions soared 38% to Rs 376. Diamond Cables, RPG Transmission, Vakrangee Software, Jindal Photo, Hinduja TMT, Mazda, Lok Housing, Goodricke, Voltas, Century Textiles, TRF, Godrej Foods, Hindustan Constructions, Shree Cement and Unitech were the other prominent gainers this week.Maxwell Industries slumped over 22% to Rs 33.25. Tulip Star, FACT, IFCI, Bombay Oxygen, Jain Studios, Chambal Fertilisers, GNFC, Nagarjuna Fertilisers and Godavari Fertilisers were the major losers this week. FIIs' net buying in the first four days of the week totalled Rs 1,807 crore (gross buying - Rs 8,052 crore; gross selling - Rs 6,245 crore;).FIIs were net buyers to the tune of Rs 7,590 crore in February. Their total buying for 2006 till March 2 amounts to a whooping Rs 12,700 crore ($2.82 billion).Mutual funds (MFs), too, pressed the buy button, and their net buys totalled Rs 617 crore between February 27 - March 2 (Buying - Rs 3,460 crore; Selling - Rs 2,843 crore).Incidentally, MFs were net sellers to the tune of Rs 245.56 crore in February, and have been net sellers of shares worth Rs 1,078 crore till March 2 this year.