The Bombay Stock Exchange benchmark Sensex fell by over 36 points in early trade today as investors and funds booked profits ahead of the RBI's monetary policy review later in the day. The 30-share barometer fell by 36.77 points or 0.18 per cent to 20,318.86. It had gained nearly 415 points in the previous two sessions. Similarly, the wide-based National stock Exchange index Nifty, moved down by 13.20 points, or 0.21 per cent to 6,104.35 points at the outset.