Sensex surges 700 points: Key factors behind the bull run on Dalal Street

• Buying in banks

was the top contributor in today's market surge as it jumped over 6% on intraday basis after strong quarterly earnings show. The other top contributors were and . Nifty Bank index shot up by over 400 points and was trading at 48,599.20 around this time.

• Global Markets

While Japan's Nikkei fell sharply on Thursday amid yen wallowing at a fresh three-decade low above 155 per dollar, the other major Asian indices traded in the green. China's Shanghai Composite closed higher by 0.30% while Hong Kong's Hang Seng index also gained by nearly half a percentage point. Markets in Bangkok and Manila also edged up.

Among major European markets UK's FTSE 100 was higher by 51.67 points or 0.64% and traded at 8,092.05 around this time.

• Monthly Expiry

Today is also the day of monthly expiry and the May series begins tomorrow. Investors tend to square off positions ahead of expiry.

According to the derivatives data analysed by SBI Securities, for April monthly series, 22400 call has significant open interest, followed by 22500 strikes. On the put side, 22400 has significant open interest, followed by 22300 strike implying the zone of 22330-22300 will act as immediate support for the index. On the upside, the level of 22445 will act as immediate resistance for the index. The brokerage had predicted that any sustainable move above the level of 22,445 would lead to further upside rally in the index.

More to come...