Yellen: Global 'risks' could hurt US economy

While Federal Reserve Chair Janet Yellen yesterday spoke optimistically about the U.S. economy, she said the global economy could pose a problem.

"Global developments pose ongoing risks," Yellen said at the Economic Club of New York.

Her biggest worries are China and oil.

She said uncertainty over China's economic slowdown and the direction of its currency, the yuan, contributed to the market meltdown at the beginning of the year when the Dow lost about 2,000 points.

According to CNNMoney, her remarks also made an interest rate hike at the Fed's next meeting in April seem unlikely.

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