Why did Sensex fall nearly 990 points from its day's high today?

BSE Sensex and Nifty 50 fell nearly 990 and 280 points from their day's highs on Monday, respectively. This comes as the RBI raised banks' minimum daily Cash Reserve Ratio (CRR) maintenance to 99% and announced a ₹25,000-crore bond sale. Profit booking in IT shares, elevated crude oil prices, rising US and global bond yields and FII outflows also contributed.