Dealers said the research outfit owned by a leading foreign institutional investor (FII), who is also an active player in the market, has upgraded it's recommendation on this stock from "hold" to "buy". This along with huge buy orders by another leading FII (about four lakh shares) and value buying by retail investors, helped this counter to end the day by more than 6.50 per cent at the bourses.The Infosys counter also witnessed huge volumes throughout the day. At BSE, this counter attracted trading volumes of more than 15 lakh shares, while at NSE it recorded volumes of more than 16 lakh shares. Combined turnover at both the bourses stood at Rs 1,755.67 crore, which was 16 per cent of the combined turnover of Rs 10,889 crore, BSE-NSE taken together. At the BSE, the stock reached a high of Rs 6,214 and an intra-day low of Rs 5,826 before closing at Rs 6,171.45, gaining 6.44 per cent while at the NSE it remained at a high of Rs 6,214.65 and a low of Rs 5,820 before closing at Rs 6,185, gaining 6.62 percent.

Dealers also said that the ADR of company gained heavily at the tech-heavy Nasdaq which gained 9.10 per cent on Friday last. The Nasdaq Composite Index also gained substantially during the last week. Monday's buying in this counter at the domestic market was to bring it to the parity it's ADR price which crossed $100 mark on Friday night.

This counter was in the limelight last month when it was hammered down to a 52-week low of Rs 5,505.10 at the BSE and at Rs 5,488.25 at the NSE. Due to it's heavy weightage in both the benchmark indices, the market also felt the brunt and came down heavily.

On Monday again, because of the same weightage it could prevent the downfall of the market when other heavyweights like HLL, ITC and L&T were down, said the dealers.