WASHINGTON — Despite signs of improvement in the job market, the chairman of the Federal Reserve, Ben S. Bernanke, and most other Fed officials signaled Wednesday that they remained cautious about easing back too quickly on their efforts to stimulate the economy.

While some Fed policy makers suggested that the central bank could begin reducing its monthly purchases of government bonds as early as next month, most still want to see continued evidence of an upswing in the job market and a decline in unemployment first, according to minutes of the most recent meeting of the Fed’s policy arm that were released Wednesday afternoon.

Confusion on Wall Street over the Fed’s intentions led to a topsy-turvy day in the stock market. The major indicators were up in the morning after Mr. Bernanke testified to a Congressional committee but then fell sharply after the meeting minutes were disclosed.

In his testimony, Mr. Bernanke said that ending the $85 billion monthly bond-buying effort too soon would do more harm than good.