Stocks rocketed on Wednesday in Wall Street's best day in 10 years, snapping a stomach-churning, four-day losing streak and giving some post-Christmas hope to a market that has been battered this December.

The Dow Jones Industrial Average shot up more than 1,000 points — its biggest single-day point gain ever — rising nearly 5 percent as investors returned from a one-day Christmas break.

The broader S&P 500 index also gained 5 percent, and the technology-heavy Nasdaq rose 5.8 percent.

But even with the rally, the market remains on track for its worst December since 1931, during the depths of t...