Let's skip Option chain data since it shows an obvious range of 27500 - 28000. On Charts, Banknifty (BNF, actually Niftybank- cash) finished as a red base-like candle with lower low and lower high than previous candle.On a 15 min chart, one can see that BNF did not break its low made during first 15 minutes, throughout the day. In the last one hour when Nifty was breaking its initial low, BNF didn't. Why? Look at the component banks of BNF and their charts.HDFC Bank daily chart shows that it is at 50% fibonacci level; ICICI bank shows that it is at 61.8% Fibonacci level; Kotak Bank shows that it is netween 50% & 61.8% Fibonacci level. These three contribute more than 60% to BNF. BNF itself reversed on Monday from near 78.6% level. What does this tell us? Buying would surely come in these stocks when they are at their respective critical supports. And if that happens at one time, a strong buying rally is likely push BNF up. For BNF, it might happen near 27500. But since Nifty is weak, buying could face some restraint and selling might start at levels given on 15 min chart. Which in turn means that do not take the trade immediately as soon as price enters selling area. Let the momentum slow down, let it top out and then take the trade. All the best. Happy trading.