HEAD FAKE: Stocks started higher early Thursday but turned lower within 20 minutes. Indexes in the U.S. and Europe sank after Germany's main stock index, the DAX, suddenly dipped 4 percent. Traders struggled to explain the fall.
WHITE KNIGHT: Bank of America Corp. rose 9 percent on news that Warren Buffett will invest $5 billion in the struggling bank. Other bank stocks also rose.
THE INDEXES: The S&P 500, the benchmark for most money managers, has gained 3 percent this week but is still down 10 percent for the month. Thursday's drop broke a three-day rally in which the Dow gained 503 points.