For good COs, ADR premium is supposed to be around 35-40%. Infact INFY has been traded here with a premium as high as 35% to the Indian price. Of late, there has been an imbalance and more people are noticing the difference and getting in before its too late. Quote of 47 is only a 25% premium to Indian price and may be there is a belief that there is still some room for it to go up. My 2 cents !!!
I guess it isn't about going up or down. It is going sideways between 42 to 47. I would recommend buying at 42 and selling at 46. In any case, company with sound fundamentals would not be too bad to even hold for a little while.