Wall Street plunges through 'white knuckle' zone before closing slightly higher

The Dow closed at 34,365, up more than 99 points; after a day of frenzied trading, investors were left pretty much where they stood at breakfast. The broader S&P 500 index staged its biggest intraday comeback since the 2008 financial crisis, closing up more than 12 points at 4,410. The technology-rich Nasdaq gained 86 points to end at 13,855; it is now down almost 12 percent since Jan. 1.