U.S. stocks wavered and closed lower this week, as investors digested a key speech from U.S. Federal Reserve's Chair Janet Yellen and a batch of newly-released economic reports.

For this week, the Dow fell 0.8 percent, and the S&P 500 was down 0.7 percent. The Nasdaq shed 0.4 percent, snapping eight-week winning streak.

"In light of the continued solid performance of the labor market and our outlook for economic activity and inflation, I believe the case for an increase in the federal funds rate has strengthened in recent months," said Yellen, at the Economic Policy Symposium at Jackson Hole, Wyoming.

Traders kept a close eye on her speech for more clues on the timing of the next interest rate hike. Some Fed officials' hawkish comments have strengthened market expectations that the central bank might raise interest rate later this year.

Analysts said it's possible for the Fed to hike interest rates as soon as September. But about 71 percent of 62 economists surveyed by the Wall Street Journal this month believed that the Fed would wait until December to raise rates.

The CBOE Volatility Index, often referred to as Wall Street's fear gauge, edged up 0.15 percent to end at 13.65 on Friday.

On the economic front, U.S. real gross domestic product (GDP) increased at an annual rate of 1.1 percent in the second quarter of 2016, according to the "second" estimate released by the Commerce Department Friday. In the first quarter, real GDP increased 0.8 percent.

The final reading of consumer sentiment index published by Thomson Reuters/University of Michigan came in at 89.8 for August, lower than July' s reading of 90.0.

New orders for manufactured durable goods in July increased 9.7 billion U.S. dollars or 4.4 percent to 228.9 billion dollars, according to the U.S. Commerce Department Thursday.

"Volatile components aside, this was an encouraging report," said Jay Morelock, an economist at FTN Financial.

In the week ending Aug. 20, the advance figure for seasonally adjusted initial claims was 261,000, a decrease of 1,000 from the previous week' s unrevised level, said the U.S Labor Department Thursday.

U.S. existing-home sales lost momentum in July and decreased year-over-year for the first time since November 2015, according to the National Association of Realtors Wednesday. Total existing home sales fell 3.2 percent to a seasonally adjusted annual rate of 5.39 million in July from 5.57 million in June.

U.S. new home sales also came out positive. Sales of new single-family houses in July 2016 were at a seasonally adjusted annual rate of 654,000, well above market estimates and logging the highest level since October 2007, according to the Commerce Department Tuesday.

"The number of new homes sold but not yet started rose to the highest level in nearly nine years suggesting residential construction should remain a positive contributor to growth in Q3," said Sophia Kearney-Lederman, an economic analyst at FTN Financial.

In corporate news, Pfizer agreed to buy U.S. drug company Medivation on Monday for 81.50 U.S. dollars a share, or about 14 billion dollars. Shares of the former dipped 0.40 percent to 34.84 dollars apiece Monday, while shares of the latter rocketed 19.74 percent to 80.42 dollars per share.

Before the Tuesday' s opening bell, Best Buy reported GAAP diluted earnings per share from 

Source : XINHUA