NEW YORK - Wall Street extended a huge rally Friday as investors stormed back into the market, relieved that the government plans to rescue banks from billions of dollars in bad debt. The Dow Jones industrials rose more than 375 points, giving them a massive gain of more than 785 points over two days, and Treasurys fell as money flowed into equities. 

A new ban on short selling, or placing bets that a stock will fall, was likely adding to the market's gains. And Friday was a quarterly "quadruple witching" day, which marks the simultaneous expiration of options contracts, an event that often adds to volatility. 

"A big chunk of this is scaring all the shorts to cover their bets," said Joe Battipaglia, market strategist at Stifel, Nicolaus & Co. 

Treasury Secretary Henry Paulson, speaking about the rescue plan said a bold approach is needed to remove troubled assets from the books of financial firms. He offered few details, but said he would work on it through the weekend with congressional leaders.