US Treasury yields fall after July ISM data

U.S. Treasury prices climbed on Monday, after Greek stocks sold off sharply after the market opened for the first time in five weeks, lifting demand for safe-haven assets, as a week of major data releases is also in focus.

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Markets will be focused on the U.S. jobs report on Friday, but ahead of that, July's manufacturing ISM alongside June consumer spending and income figures, the associated June PCE deflators, and July vehicle sales numbers are all due for release Monday morning.

After July ISM data came in weaker-than-expected on Monday, the yield on the benchmark 10-year Treasury notes was down 4 basis points to 2.147 percent, near a session low. The yield on the 30-year moved 6 basis points lower to 2.849 percent. When a bond's yield falls, its price rises.

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Investors will be watching August's data closely as it will likely indicate whether the U.S. Federal Reserve is getting ready to hike rates in September as many expect.

In Europe, the Athens stock exchange opened nearly 23 percent lower after reopening for the first time in five weeks, recovering some earlier losses to trade around 19.5 percent lower in mid-morning trade.

Read MoreGreek stock market trades 20% lower after reopening

Greek banking stocks were the worst hit with Alpha Bank, Attica Bank and Eurobank Ergasius, Bank of Piraeus and the National Bank of Greece all opening around 30 percent lower - the daily limit. Similar losses were seen in other stocks outside of the banking industry as well.

There was further bad news for the Greek economy, with flash manufacturing PMI figures for July down to 30.2 the lowest reading since Markit began compiling data in 1999.