First I had mentioned Gap Up n Down scenario's in Banknifty but as market opened I have changed it to one-sided scene.
(i) If trendline violated to upside wont sustain for longtime max 21650's only, then reverse to down
(ii) Touch n Play with trendline from Downside & Straight move to down
Today weekly expiry right ? Extreme guess work, BankNifty may reserve...