Investors have been cautious since June, when Fed Chairman Ben Bernanke discussed a possible retreat from the bank's $85 billion per month asset purchasing program.
Bernanke said Wednesday the labor market had shown some improvements since the Fed linked policy changes to a lower unemployment rate. But the rate does not tell the entire story, Bernanke said, pointing out that wages were flat and that a significant portion of the lower unemployment rate -- now at 7.3 percent -- was due to people dropping out of the workforce.
A chart of the Dow Jones industrial average for Wednesday says it all. The index was ahead through the day, but just barely. At precisely 2 p.m., the index charged higher, adding nearly 200 points before settling back down toward the close.
The Dow ended with a gain of 147.21 points or 0.95 percent to 15,676.94. The Standard & Poor's 500 index 20.76 points or 1.22 percent to 1,725.52.
Both indexes closed at record highs.
The previous closing high for the Dow was 15,658.36, while the S&P's previous high was 17,07.67. Both previous records were set Aug. 2.
In the interim, the markets took sharp turns lower. The Dow lost 4.6 percent in August, hitting a trough at 14,776.13 on Aug. 27. The S&P's also hit bottom on Aug. 27 at 1,630.48.
The Nasdaq composite index of tech-dominated stock added 37.94 points or 1.01 percent to 3,783.64.
On the New York Stock Exchange, 2,676 stocks advanced and 449 declined on a volume of 3.9 billion shares traded.
Ten-year U.S. treasuries soared, climbing 1 11/32 to yield 2.695 percent.
The euro fell to $1.3526, while the dollar dropped to 97.91 yen.
In Japan, the Nikkei 225 index added 193 points, 1.35 percent, to 14,505.36.
In Britain, the FTSE 100 index gave up 0.17 percent or 11.35 points to close at 6,558.82.
Gold jumped 4.2 percent to $1,364.20 per troy ounce on the Comex division of the NYMEX. Silver added 5.7 percent to reach $23.03 per ounce.
In late trading, West Texas Intermediate crude oil gained $2.66 or 2.5 percent to reach $108.08 per barrel.