Taking into account today's RBI reference rate for one US dollar at Rs 44.5855, this translates into total market valuation of $100.33 billion for the Tata group. The group's total market value stood at Rs 446,420 crore ($99.8 billion) yesterday. The Tata group comprises of nearly 100 operating companies, but only about 30 of them are listed in the stock market. These include TCS, Tata Steel, Tata Motors, Tata Power, Indian Hotels, Titan, Voltas and Tata Communications. TCS alone accounts for more than half of the group's total market value with a market capitalisation of $52 billion (Rs 2,32,194 crore). In an overall weak stock market today, when benchmark Sensex fell by 83 points, some of the Tata group companies managed to add value to their stocks. These included Rallis, Indian Hotels, Tata Communications, Tata Global Beverages, Tata Investment Corp, Trent and TCS.