Nifty 50 index has been trading in a upward parallel channel since its major fall that was a week ago. There seems to a major call OI buildup but the index has been resisting further fall with a strong support at 17950. There is high also today on a shorter time frame of 15 minutes there is it is breaching out of a symmetrical triangle pattern. Hence an upside move is likely trapping at least 20 million call writers. There might also be a possibility of downside, i estimate that to be 20 percent due a few negative results of companies.