U.S. stocks ended a holiday-shortened week with the Standard & Poor’s 500 making its biggest weekly gain in nine months. For the four days, the S&P 500 added 2.7 percent and both the Dow Jones industrial average and the Nasdaq Composite advanced 2.4 percent.

The weekly result is worth noting because it marks a strong turnaround after six weeks of turmoil that primarily affected overpriced information technology, biotechnology and other issues, mostly in the Nasdaq Composite.

By the end of last week, the bursting of that bubble was showing an increasing tendency for the selling to spread to the broad market. That hasn’t happened, at least not yet. In its reversal from an oversold condition, the market benefited from several developments:

#1: Better-than-expected corporate earnings reports. Less than one-fifth of the companies in the S&P 500 have reported results so far. But 63 percent of those have beat earnings expectations, according to Thomson Reuters. That exceeds the 56 percent average over the last four quarters.

#2: Improving economic data. The number of Americans filing new claims for unemployment benefits stayed low. It rose only slightly from the 6-1/2-year bottom touched the previous week. And the four-week moving average for new claims, which reduces week-to-week distortions, hit its lowest level since October 2007.

The Federal Reserve’s April survey of economic activity in its 12 districts around the country states that there has been a pickup in most areas, particularly consumer spending as weather conditions improved. Another Fed report cited the highest reading for capacity utilization among companies in nearly six years. And the Federal Reserve Bank of Philadelphia said its business activity index increased to 16.6 this month from 9 in March, marking the highest reading in seven months.

However, this week also brought reports on housing starts and building permits for March that were weaker than expected.

#3: Continued easy monetary policy. Even though an improving economy may lie ahead, Federal Reserve chairwoman Janet Yellen reiterated this week that she expects interest rates to remain very low until the recovery is on a stronger foundation. She said that while “the recovery has come a long way,” aided by a housing rebound and a resurgent auto industry, a robust and healthy job market appears to be “more than two years away.”

She emphasized that even though the official unemployment rate has fallen steadily and is now 6.7 percent, other job-market measures remain weak. Most notable here are the number of people forced to take part-time jobs because they can’t find full-time work; a disproportionately high percentage of low-paying jobs; a large number of long-term unemployed; and the proportion of the population that has dropped out of the work force.

Yellen’s comments seem to clarify her remarks last month during her first news conference as Fed chairwoman that suggested the central bank might start to raise the short-term interest rates it controls, which have been in the 0-0.25 percent range since December 2008, as soon as mid-2015.

Yellen this week emphasized that the Fed must remain flexible enough to respond to what she called the “twists and turns” of a still-recovering economy. As she noted, “We have indeed had a disappointingly slow recovery, and our consistent expectations for a pickup in growth have been dashed over a number of years.”

Moreover, risks of deflation remain. The Fed’s favorite inflation measure, the price index for personal consumption expenditures, increased just 0.9 percent in the 12 months through February, the latest report said. This is well below the Fed’s target inflation rate of 2 percent.

“Once it starts, deflation can become entrenched and associated with prolonged periods of very weak economic performance,” she said. “With longer-term inflation expectations anchored near 2 percent in recent years, persistent inflation well below this expected value increases the real burden of debt for households and firms, which may put a drag on economic activity.”

As always, risk abounds. But the overall outlook remains more positive than not, with respectable economic growth, subdued inflation and interest rates, and generally reasonable equity valuations.