Stocks ripped higher to close near their best levels Wednesday, with the Dow and S&P 500 setting fresh highs, after the Federal Reserve surprised Wall Street by keeping its $85 billion-a-month bond-buying program intact. (Read more: After-hours buzz:Oracle, McDonald's, Cisco & more) "This has been music to the market's ears and a positive for risk assets across the board," said Quincy Krosby, market strategist at Prudential Financial. "But investors at some point will start to question the strength of the underlying economy...The chairman also did indirectly point to fiscal policy and no doubt he's following events in DC and the headline drama playing out on the budget debates so that could also have been a reason he decided to hold off now."

Major U.S. Indexes

The Dow Jones Industrial Average soared 147.21 points, or 0.95 percent, to end at 15,676.94, lifted by Alcoa and Home Depot. The blue-chip index set a fresh intraday-high of 15,709.58. The spiked 20.76 points, or 1.22 percent, to close at 1,725.52, after hitting an all-time high of 1,729.44. Both indexes posted their best day since June 13. The Nasdaq rallied 37.94 points, or 1.01 percent, to finish at 3,783.64. The CBOE Volatility Index (VIX), widely considered the best gauge of fear in the market, fell near 13. All key S&P sectors closed in positive territory, propelled by materials and utilities.