Shares of the country's second largest company by market capitalisation, Tata Consultancy Services (TCS), rose as much as 2.25 per cent to hit an intraday high of Rs 3,944.40 on the BSE a day after it announced its biggest-ever Rs 18,000 crore share buyback proposal. The company will buy shares from its existing investors at Rs 4,500 per share, marking a premium of 17 per cent to its yesterday's closing price.