The world's economic 'canary in the coal mine' just flashed a misleading signal

The world's economic 'canary in the coal mine' surprised on the upside - but it might just be a blip.

South Korean exports rose 2.6% year-over-year in August, above expectations of a 0.6% increase, and a significant improvement from July's 10.3% drop.

This was the first year-over-year growth since December 2014 - so it seems like a good sign.

However, Barclays' David Fernandez and Angela Hsieh noted that the improvement was due mostly to a working day distortion and a low base.

"All in, we see little momentum for a meaningful rebound, given the backdrop of sluggish global demand conditions and ongoing price pressures on Korea's key export goods," they wrote.

"In the absence of a calendar day advantage (one fewer working day in September) as well as payback after the August vessel delivery, we expect exports to weaken again in September."

The South Korean won finished down by 0.7% at 1,121.78 per dollar.

Korean exports are often referred to as the world's economic canary in the coal mine, or a preview of what's to come, by economists both because of their heavy exposure to the US, China, and Japan, some of the world's biggest economies, and because the data comes out on the first day of each month.

As for the rest of the world, here's the scoreboard as of 8:03 a.m ET:

• The British pound is stronger by 0.8% at 1.3243 against the dollar after the latest manufacturing PMI data surprised on the upside. The reading came in at 53.3, above the forecast of 49.0, and above July's 48.3.
• The euro is little changed at 1.1147 against the dollar after several PMI readings. German PMI came in line with expectations at 53.6, and Spanish PMI came in at 51.0, slightly above the forecast of 50.9. However, Italian and French PMI both disappointed, coming in at 49.8 and 48.3, respectively.
• The Russian ruble is little changed at 65.2629 per dollar after the latest PMI reading came in at 50.8, compared to last month's 49.5.
• The US dollar index is little changed at 95.98 ahead of a busy data day. Productivity and initial jobless claims will be released at 8:30 a.m. ET before manufacturing PMI crosses the wires at 9:45 a.m. ET. Then, at 10 a.m. ET, construction spending and ISM manufacturing will be announced. US vehicle sales will be reported throughout the day.