The Indian equity benchmarks staged a gap down opening on Monday with the Sensex dropping over 550 points and Nifty dropping below its important psychological level of 16,900 as investors confidence was dented by rising Omicron cases while banking shares saw a selloff after corporate governance issues surfaced at private sector lender RBL Bank. Meanwhile, other Asian markets were also trading lower as uncertainty over the economic impact of the Omicron coronavirus variant weighed on investor sentiment, news agency Reuters reported.