Stocks post sharp weekly losses after 4th straight down day

Stocks tumbled Friday as Wall Street suffered a fourth straight day of losses and sent the major indexes down more than 2% for the week.

The broader market slumped despite a 10% surge in Amazon.com (AMZN) shares on stronger-than-expected earnings. Late Thursday, the e-commerce giant reported a surprise second-quarter profit instead of a loss. Its rally Friday lifted Amazon market capitalization above that of retailing titan Walmart (WMT) and Chinese e-commerce rival Alibaba (BABA). Shares closed up $47.25 to $529.43 after earlier hitting an intraday record of $580.57.

The Dow Jones industrial average dropped 163 points, or 0.9% to 17,569 and the Standard & Poor's 500 index fell 22 points, or 1.1%, to 2080. The Nasdaq composite index tumbled 57 points, or 1.1%, to 5089. For the week, the Dow tumbled 2.9%, the S&P 500 2.2% and the Nasdaq gave back 2.3%.

Oil prices dropped further below $50 a barrel as U.S. benchmark crude fell 31 cents to close at $48.14 a barrel in New York. Oil was down more than 5% for the week.

Wall Street has been under pressure this week as several high-profile blue-chip stocks such as McDonald’s (MCD), Caterpillar (CAT) and 3M (MMM) reported disappointing earnings.

Friday, one of the big earnings disappointments was the biotechnology company Biogen (BIIB), which sent its shares tumbling 21% after it reported second-quarter results below expectations and slashed its full-year profit and revenue forecasts.

News of another big deal in the health insurance industry also did little to help the broader market. Anthem (ANTM) said it is buying rival Cigna (CI) in a $54 billion deal that will create a mammoth for-profit insurer. Anthem shares fell 3% and Cigna dropped 6%

Investors were also anxious the upcoming Federal Reserve meeting and the prospects of interest rate hikes. Policymakers begin a two-day meeting on July 28.

Overseas, European markets were sharply lower as Britain’s FTSE 100 was down 1.1%, Germany’s DAX fell 1.4% and France’s CAC 40 dropped 0.6%.

Asian markets also fell:  Japan’s Nikkei 225 was down 0.7%, while Hong Kong’s Hang Seng was down 1%. China’s Shanghai Composite Index rose 0.6%.

Those drops followed weaker-than-expected purchasing managers index readings in German, France and China. In the case of China, it was the fifth straight month of contraction and the PMI's lowest level in 15 months.