NEW YORK (AP) — U.S. stocks fell Friday morning following a surprisingly weak jobs report and more signs that the global economy is hitting the brakes.

The S&P 500 was on track for its fifth straight decline, which would be its longest losing streak in nearly four months. It followed the lead of other markets around the world after Chinese stocks plunged amid worries about slowing economic growth there. Just a day earlier, investors’ concerns were focused on Europe after the central bank there slashed its forecast for economic growth this year.

The market’s momentum has stalled this week after enjoying a sharp bounce back at the start of this year. This week’s losses for the S&P 500 are the worst since December, but not as severe as they were then, when worries were peaking about a slowing global economy and that interest rates may rise too quickly. Since then, the Federal Reserve helped calm some of the worries by pledging to be patient in raising rates.

Analysts are debating whether these latest moves are the last gasps for the longest bull market on record for U.S. stocks, which began 10 years ago this weekend, or just the latest challenge for it muddle through.

KEEPING SCORE: The S&P 500 was down 0.6 percent as of 11 a.m. Eastern time. The Dow Jones Industrial Average lost 107, or 0.4 percent, to 25,365, and the Nasdaq composite fell 0.6 percent. The S&P 500 was on pace for just its second losing week since late December.

JOB WOES: The strong U.S. labor market has been a major pillar of support for the stock market’s run in recent years, but Friday’s jobs report was surprisingly bad.

Employers added just 20,000 jobs last month, when economists were expecting something closer to 180,000. Last month’s job growth is also a sharp slowdown from January’s 311,000, a number that the government revised higher on Friday.

Some economists said the surprisingly weak number was merely a reversal from the exaggerated strength in earlier months, and bad weather hitting the construction and other industries perhaps exacerbated it. They debated how worried to be about the number.

The report also showed that average hourly pay for workers rose 3.4 percent last month from a year earlier. It was the strongest wage growth since 2009.

GLOBAL PAIN: Stocks in Shanghai sank 4.4 percent Friday after a report showed that Chinese exports plunged 20 percent last month, far more than economists expected. It’s just the latest wild move for a market that is notoriously volatile. The Shanghai index is still more than 19 percent higher for the year, even with Friday’s plunge.

The dour report on China’s economy, the world’s second-largest, fed into growing worries about the health of the overall global economy. The Organisation for Economic Co-operation and Development said this week that it expects global growth to be 3.3 percent this year, down from the 3.5 percent that it had forecast just four months ago.

The OECD said economic prospects are weaker in nearly all the countries that make up the G20, and it cited a slowdown in trade and global manufacturing, among other reasons. The United States and China have been locked in a particularly tense trade dispute, though the countries say they’re making progress in negotiations.

SLICKED: A slower global economy wouldn’t need as much oil, and the price of crude sank with expectations for demand. Benchmark U.S. crude fell $1.60, or 2.8 percent, to $55.07 per barrel. Brent crude, the international standard, lost $1.69 to $64.61 per barrel.

The sharp losses sent energy companies to the worst performance among the 11 sectors that make up the S&P 500. They were down 2.1 percent.

Also hurting the sector was a decision by Norway’s $1 trillion wealth fund to dump shares in some oil and gas companies. The move would exclude companies that operate solely in exploration or production, but it will continue to own the biggest companies in the energy industry.

EOG Resources fell 4.2 percent, Marathon Oil lost 4 percent and Noble Energy sank 4.4 percent.

BUYING IN BULK: Costco Wholesale bucked Wall Street’s downward trend and rose 5.1 percent for the biggest gain among stocks in the S&P 500. It reported profit growth for the latest quarter that was far stronger than analysts expected.